Hobby Charger?

[Faynard]

I've been wanting to try some Li-ion's in my flashlights, but with my small collection so far, I would need at minimum two different chargers. The Pila IBC alone being $50, I really don't want to pay that much and not be able to charge everything.



I recently learned that a 'hobby charger' can charge all of the types that I am looking for - 10440, 14500, rcr123, 18650, and even eneloops (!!!). However, I am a bit out of my league with all of this magnets, balancing, DIY cradles and such. I don't want to pay a lot (under $50 would be good, closer to $20 would be ideal if such a thing is possible). I don't mind some learning curve. I probably wouldn't charge more than one cell at a time, and I can't imagine being motivated enough to make a DIY cradle. I am not too experienced with soldering, though I'm sure could manage something simple if I needed to.



Please advise? Is there a product out there for me that won't require me to be an electrician? :nana:



Thanks in advance! :bow:

 

[tandem]

Posts following were recovered from Google cache


Hobby Charger?
Written by Faynard on 01-03-2011 12:19 PM GMT

I've been wanting to try some Li-ion's in my flashlights, but with my small collection so far, I would need at minimum two different chargers. The Pila IBC alone being $50, I really don't want to pay that much and not be able to charge everything.

I recently learned that a 'hobby charger' can charge all of the types that I am looking for - 10440, 14500, rcr123, 18650, and even eneloops (!!!). However, I am a bit out of my league with all of this magnets, balancing, DIY cradles and such. I don't want to pay a lot (under $50 would be good, closer to $20 would be ideal if such a thing is possible). I don't mind some learning curve. I probably wouldn't charge more than one cell at a time, and I can't imagine being motivated enough to make a DIY cradle. I am not too experienced with soldering, though I'm sure could manage something simple if I needed to.

Please advise? Is there a product out there for me that won't require me to be an electrician? :nana:

Thanks in advance! :bow:

Re: Hobby Charger?
Written by flatline on 01-03-2011 01:38 PM GMT

Magnets will stick to the alligator clips and the cells. No soldering required.

However, you may find such an arrangement a little finicky to deal with if you use it often.

--flatline


Re: Hobby Charger?
Written by Faynard on 01-03-2011 01:45 PM GMT

Magnets will stick to the alligator clips and the cells. No soldering required.

However, you may find such an arrangement a little finicky to deal with if you use it often.

--flatline

A little finicky, yes - but well worth it for the flexibility it would give me - not only all the different sizes, but even different chemistry types. Also, I don't think I really would use it that often, maybe a few times a week? A little finicky, yes - but well worth it for the flexibility it would give me - not only all the different sizes, but even different chemistry types. Also, I don't think I really would use it that often, maybe a few times a week?

Any suggestions for products, or places I can shop for such a thing? Or ideas of features and specs that I should look for, or don't need?


Re: Hobby Charger?
Written by jasonck08 on 01-03-2011 02:33 PM GMT

If you want a cheap good Hobby charger, your best bet would be the ternegy accucel 6 from hobby city. It's about $22 + $12 or so shipping.

Thats what I currently use to charge Li-ion, Lifepo4, IMR, Ni-mh, and even lead acid batteries from time to time.

I primarily just use magnets for charging, but I also made a pretty simple clamp that works also.

Re: Hobby Charger?
Written by pae77 on 01-03-2011 07:04 PM GMT

Here's some info that may help the OP out a bit:link.


Re: Hobby Charger?
Written by DEERSLAYER on 01-03-2011 11:06 PM GMT

Here's some info that may help the OP out a bit: link.

Thanks for the link pae77. I get the impression that is a better, safer charger than the Pila and that I could turn it on and leave the house with out having to worry. Thanks for the link pae77. I get the impression that is a better, safer charger than the Pila and that I could turn it on and leave the house with out having to worry.


Re: Hobby Charger?
Written by tobarger on 01-03-2011 11:42 PM GMT

Can the Accucel-6 be programed to handle 3.0v lithium batteries?

If not than is there a hobby charger that will.


Re: Hobby Charger?
Written by hoongern on 01-04-2011 05:39 AM GMT

Can the Accucel-6 be programed to handle 3.0v lithium batteries?

If not than is there a hobby charger that will.

Maybe you're using the wrong name, but 3.0v lithium cells CANNOT be charged!!! (I would take this to refer to the primary CR123 cells - Lithium cells and Lithium-Ion cells are completely different) Maybe you're using the wrong name, but 3.0v lithium cells CANNOT be charged!!! (I would take this to refer to the primary CR123 cells - Lithium cells and Lithium-Ion cells are completely different)

On the other hand, if you mean 3.2V LiFePO4 Li-Ion cells, then definitely a yes :)

If you mean 3.7V LiCo cells which have a diode, I'm not sure what charging specifications they need, so I'll let someone else answer this if these are the cells you are referring to.

The Accucel-6 can handle:

3.2V Li-Ion (LiFePO4)

3.6V Li-Ion (Charges to 4.1V)

3.7V Li-Ion/LiPo (Charges to 4.2V)

1.2V Ni-Cad/Ni-Mh (up to 15 in series)

2-20V Lead Acid

As for how I charge my cells, I use the magnet method, but in my case, I got magnets small enough to fit inside the alligator clips, meaning that I don't have to attach the magnets first and then the clips to the magnets. Easier :)

I get the impression that is a better, safer charger than the Pila and that I could turn it on and leave the house with out having to worry.

As with all Li-Ion chargers, there is always room for error, and I would not leave the house with it charging. That said, I don't see any reason why a hobby charger should fail to terminate. It's just - better safe than sorry As with all Li-Ion chargers, there is always room for error, and I would not leave the house with it charging. That said, I don't see any reason why a hobby charger should fail to terminate. It's just - better safe than sorry :)

As far as actual models go, I use the Turnigy Accucel-6, which I think is one of the best deals for your money! I used to have 4 different cradle chargers for various battery types, and now I just have one hobby charger - much neater :D

And if you need a 2nd charging channel, you could always buy a 2nd hobby charger.. hehe.

The only thing with the Turnigy is that it requires an external 12V power supply. In my case, it was no problem, I already had one lying around. Another solution I had was to connect 2 wires to my desktop computer power supply's 12V rail. Voila - instant "free" 12V power supply.


Re: Hobby Charger?
Written by Faynard on 01-04-2011 08:40 AM GMT

Thanks Pae77, that link is just what I needed! I'm just about ready to pull the trigger now, with one last question.

The "Turnigy Accucel-6" has no power supply? Is there a model that includes it? Or a separate one that comes recommended? I see people using laptop bricks, but I don't have any extras that I could use.


Re: Hobby Charger?
Written by tobarger on 01-04-2011 09:54 AM GMT

Can the Accucel-6 be programed to handle 3.0v lithium batteries?

If not than is there a hobby charger that will.

I am referring to this type of battery, listed at 3.0v. I am referring to this type of battery, listed at 3.0v.

Tenergy RCR123A 3.0v 750mAh LiFePo4
http://www.batteryjunction.com/2rc375reliba.html

The Turnigy Accucel-6 manual mentions LiFe(3.3V).
Do the Accucel-6 parameters need to be changed when using theses batteries?


Re: Hobby Charger?
Written by tobarger on 01-04-2011 10:26 AM GMT

Thanks Pae77, that link is just what I needed! I'm just about ready to pull the trigger now, with one last question.

The "Turnigy Accucel-6" has no power supply? Is there a model that includes it? Or a separate one that comes recommended? I see people using laptop bricks, but I don't have any extras that I could use.

http://www.hobbycity.com/hobbycity/s...idProduct=6477

This looks like the one that works best, judging by the reviews.

No issues with quality or voltage regulation.


Re: Hobby Charger?
Written by tobarger on 01-04-2011 10:34 AM GMT

Anyone having fan noise issues with the Turnigy Accucel-6?

It looks like a typical IC cooling fan that might be replacable with a part available from RadioShack.


Re: Hobby Charger?
Written by tandem on 01-04-2011 10:41 AM GMT

I believe pae77 and others have lubricated the shaft on their fan with good results.

Re: Hobby Charger?
Written by LetThereBeLite on 01-06-2011 10:58 PM GMT

Anyone having fan noise issues with the Turnigy Accucel-6?

It looks like a typical IC cooling fan that might be replacable with a part available from RadioShack.

Yes, lots of people have issues with the fan noise. It is a very well known problem. Grease/lubricate the fan and it should become quieter. Yes, lots of people have issues with the fan noise. It is a very well known problem. Grease/lubricate the fan and it should become quieter. :)

 

[tandem]

Re: Hobby Charger?
Written by hoongern on 01-07-2011 04:58 AM GMT

Yes, lots of people have issues with the fan noise. It is a very well known problem. Grease/lubricate the fan and it should become quieter. :)

Haha, am I weird for not bothering about this problem? I don't mind that the fan is loud so that I know that the charger is on and charging. Haha, am I weird for not bothering about this problem? I don't mind that the fan is loud so that I know that the charger is on and charging. :D But I agree, it can be an annoyance, but one which is probably easily fixed.


Re: Hobby Charger?
Written by pae77 on 01-07-2011 06:15 PM GMT

I kind of doubt the fan is even necessary. I've never noticed my Accucell 6 ever get even warm, much less hot. I don't charge at very high rates, usually never above 1.2 A, however. But I've often wondered about perhaps disconnecting the fan from the PCB. . . and seeing if the unit continued to run cool. But lubing the fan shaft occasionally keeps mine running quietly enough that it is not really a concern. In order to lube the shaft, you have to remove the fan to get access to the shaft. It's easy though and just requires a small Phillips screwdriver.

Aside from helping it run quieter, lubrication should help it last longer. I think it may be difficult to locate a replacement that is as small as the original. I guess if/when mine stops functioning, I'll find out whether it really is necessary or not. :eek:

Re: Hobby Charger?
Written by LetThereBeLite on 01-07-2011 06:31 PM GMT

I kind of doubt the fan is even necessary. I've never noticed my Accucell 6 ever get even warm, much less hot.

The Thundar AC6 does not even have a fan. The Thundar AC6 does not even have a fan.


Re: Hobby Charger?
Written by LumenHound on 01-07-2011 09:55 PM GMT

http://www.hobbycity.com/hobbycity/s...idProduct=6477

This looks like the one that works best, judging by the reviews.

No issues with quality or voltage regulation.

It works very well. I snagged one when I purchased an Accucel-8 from HobbyKing last year and now it powers my Accucel-6. Good deal for just a ten-spot. It works very well. I snagged one when I purchased an Accucel-8 from HobbyKing last year and now it powers my Accucel-6. Good deal for just a ten-spot.


Re: Hobby Charger?
Written by VegasF6 on 01-07-2011 10:35 PM GMT

Wow, for 10 bucks I wish I had bought one of those power supplies when I purchased theiCharger 106b+ from them. I commend you for considering a hobby charger, the quality and versatility make them so worth while. I tried desperately to talk a friend of mine in the Turnigy just weeks ago, instead of this turd:


Re: Hobby Charger?
Written by VidPro on 01-08-2011 08:21 AM GMT

The strangest thing happened this week.

i have 2 Tenergy RC hobby chargers, the small one and the bigger one (250W)

i was testing a cell i had in, and things werent going as i would have expected.

After much testing

I realised that the 2 chargers differed in the discharge test by a lot

a 9 amp battery read that it discharged ~9200 on the small one, and only ~8300-8700 on the large one, at the exact same current using the exact same wiring.

looks like (as usual) if i was going to Compare something, it will have to be with the same Junk.


Re: Hobby Charger?
Written by VidPro on 01-08-2011 08:25 AM GMT

Anyone having fan noise issues with the Turnigy Accucel-6?

It looks like a typical IC cooling fan that might be replacable with a part available from RadioShack.

Yes it is the worst fan in the world, and so are most of the under 40mm fans. when we use tiny fans in the computer chipsets and all they die 3-4 times faster than 80mm and 120mm fans with ball bearings. Yes it is the worst fan in the world, and so are most of the under 40mm fans. when we use tiny fans in the computer chipsets and all they die 3-4 times faster than 80mm and 120mm fans with ball bearings.

one person just removed it, if i removed it i would probably just drill a few holes here and there to get a nice chimney effect going to keep the air passing through.


Re: Hobby Charger?
Written by pae77 on 01-08-2011 08:25 AM GMT

Thanks Pae77, that link is just what I needed! I'm just about ready to pull the trigger now, with one last question.

The "Turnigy Accucel-6" has no power supply? Is there a model that includes it? Or a separate one that comes recommended? I see people using laptop bricks, but I don't have any extras that I could use.

These These ebay power supplies cost about $8.50 with free shipping and work great with the Accucell 6.


Re: Hobby Charger?
Written by pae77 on 01-08-2011 08:37 AM GMT

Thanks for the link pae77. I get the impression that is a better, safer charger than the Pila and that I could turn it on and leave the house with out having to worry.

I think they are better then the Pila but I still wouldn't leave the house with it running. However, you can just press the stop button to pause charging, or even shut off the power entirely, when going out for a while and then when you return simply resume charging right where you left off as these chargers will always start up in the appropriate part of the cycle depending on the SOC of the particular cell(s) being charged. So there is no reason to leave them running unattended and I wouldn't recommend doing that just in case something goes wrong. I don't leave them running unattended. Better safe than sorry. I think they are better then the Pila but I still wouldn't leave the house with it running. However, you can just press the stop button to pause charging, or even shut off the power entirely, when going out for a while and then when you return simply resume charging right where you left off as these chargers will always start up in the appropriate part of the cycle depending on the SOC of the particular cell(s) being charged. So there is no reason to leave them running unattended and I wouldn't recommend doing that just in case something goes wrong. I don't leave them running unattended. Better safe than sorry.


Re: Hobby Charger?
Written by Mark_Larson on 01-08-2011 01:12 PM GMT

I think they are better then the Pila but I still wouldn't leave the house with it running. However, you can just press the stop button to pause charging, or even shut off the power entirely, when going out for a while and then when you return simply resume charging right where you left off as these chargers will always start up in the appropriate part of the cycle depending on the SOC of the particular cell(s) being charged. So there is no reason to leave them running unattended and I wouldn't recommend doing that just in case something goes wrong. I don't leave them running unattended. Better safe than sorry.

I'm guessing that the cells should be disconnected physically at the same time as well? I'm guessing that the cells should be disconnected physically at the same time as well?


Re: Hobby Charger?
Written by LetThereBeLite on 01-08-2011 03:04 PM GMT

I watched some videos on youtube showing lithium cells exploding under various circumstances. It's pretty scary. :eek: I had no idea they were this dangerous.


Re: Hobby Charger?
Written by radellaf on 01-08-2011 03:25 PM GMT

Yes it is the worst fan in the world...if i removed it i would probably just drill a few holes here and there to get a nice chimney effect going to keep the air passing through.

I'm not sure what the options are for heatsinking the mosfet (SO-8?) but I guess the fan was cheaper. I'd think if you just ran some copper to the aluminum case, that would work. I'd be tempted as the last thing I want is to listen to ANY fan on a battery charger. I'm not sure what the options are for heatsinking the mosfet (SO-8?) but I guess the fan was cheaper. I'd think if you just ran some copper to the aluminum case, that would work. I'd be tempted as the last thing I want is to listen to ANY fan on a battery charger.


Re: Hobby Charger?
Written by tandem on 01-08-2011 03:48 PM GMT

I get the impression that is a better, safer charger than the Pila and that I could turn it on and leave the house with out having to worry.

By virtue of having more controls, no matter what the quality of a "hobby" charger is, there is more room for error. By virtue of having more controls, no matter what the quality of a "hobby" charger is, there is more room for error.

The Pila having no user inputs to get wrong, is inherently safer. That isn't a comment on the Accucel or the Bantam it is patterned after but a nod towards simpler being safer.

The Pila does one thing and it does it well - it charges 1 or 2 lithium ion cylindrical cells properly, the first time, every time.

Myself I would not leave either running while I am not at home.

 

[tandem]

Re: Hobby Charger?
Written by KiwiMark on 01-08-2011 11:56 PM GMT

The Pila does one thing and it does it well - it charges 1 or 2 lithium ion cylindrical cells properly, the first time, every time.

Yes, but only if those 1 or 2 Li-ion cylindrical cells are the right type, size & capacity. Yes, but only if those 1 or 2 Li-ion cylindrical cells are the right type, size & capacity.

For me the Hobby charger is a brilliant device, I use my 2 hobby chargers to charge my NiCd, NiMH & Li-ion cells. The Li-ion cells alone include:

10440 LiCo

14500 LiCo

16340 LiCo & LiFePO4

18650 LiCo & LiMN

26500 LiMn

36650 LiCo

I also use them to charge my 10Ah D cell NiMH batteries and my 4Ah D cell NiCd batteries.

The Pila charger just can't match that versatility.

You could even use the Turnigy Accucell-6 to charge your car battery - 12V Lead acid would be no problem, set it to 4A and when the volts get too high the charger will lower the amps to keep it within 50W. It's a pretty smart charger for what it costs!


Re: Hobby Charger?
Written by tandem on 01-09-2011 09:34 AM GMT

Definitely a "hobby" or multi-chemistry charger is hugely versatile, you'll get no argument from me on that. My point is that the versatility introduces potential for human error. To borrow from your car battery example: Charge your li-ion cells on the lead acid setting by accident and ...
:poof:

october1 earlier had mused that the Accucel somehow looked safer than a Pila. Maybe this opinion was formed due to the Turnigy's LCD display or apparent "higher tech-i-ness" of the hobby charger as opposed to the Pila's purposefully simple face -- I'm really not sure what prompted that particular dotted line connection but it isn't the case at all.

Again I'm not arguing that the Turnigy features or electronics are less safe - I've got no reason to believe that. It is the versatility and human factor introduced because of that versatility that makes such a charger potentially less safe. Used properly, I would assume and hope it is as safe as the Pila.


Re: Hobby Charger?
Written by KiwiMark on 01-09-2011 01:26 PM GMT

Definitely a "hobby" or multi-chemistry charger is hugely versatile, you'll get no argument from me on that. My point is that the versatility introduces potential for human error. To borrow from your car battery example: Charge your li-ion cells on the lead acid setting by accident and ...
:poof:

Again I'm not arguing that the Turnigy features or electronics are less safe - I've got no reason to believe that. It is the versatility and human factor introduced because of that versatility that makes such a charger potentially less safe. Used properly, I would assume and hope it is as safe as the Pila.

A cautious user that reads the display will have no problem, not only does the display provide info as you start charging, it gives a readout of what it is doing the whole way through. So if you hang around and check on the progress you will catch any problem due to your absent-mindedness before anything goes wrong. Of course if you rush through the start paying no attention to the display and then walk away and leave the charger unattended for a few hours . . . of course that involves a lot of recklessness from the human. A cautious user that reads the display will have no problem, not only does the display provide info as you start charging, it gives a readout of what it is doing the whole way through. So if you hang around and check on the progress you will catch any problem due to your absent-mindedness before anything goes wrong. Of course if you rush through the start paying no attention to the display and then walk away and leave the charger unattended for a few hours . . . of course that involves a lot of recklessness from the human.

Personally I regard the hobby chargers as something that requires a little more thought & attention because they are so versatile, but I consider them very safe, given the necessary attention. I would rate them no less safe than a charger that has a switch that you much check is in the right position (like a LiCo-LiFePO4 switch) or 2 chargers sitting on a bench, one designed to charge your normal LiCo cells and the other one for your special 3V (voltage dropping circuit) cells where you need to make sure you put the right cells in the right charger.

I wouldn't hesitate to recommend a hobby charger to anyone that uses Li-ion batteries, but there are some people to whom I'd recommend they stick with Eneloops and steer them away from switching to Li-ion. I think that the hobby chargers are safer to use than any lithium based batteries, people that aren't careful enough for hobby chargers really aren't careful enough to be using Li-ion.



Re: Hobby Charger?
Written by Mark_Larson on 01-09-2011 01:35 PM GMT

people that aren't careful enough for hobby chargers really aren't careful enough to be using Li-ion.

I agree that Li-ion cells are nowhere near mature for this particular application - there are just too many inherent dangers of the technology, compounded by the lack of protection circuits and the "pressure vessel" nature of most high-end flashlights. I agree that Li-ion cells are nowhere near mature for this particular application - there are just too many inherent dangers of the technology, compounded by the lack of protection circuits and the "pressure vessel" nature of most high-end flashlights.

If you are willing to only get 18650's of 1500 mAh or greater capacity, a Pila charger will work well for you. As soon as you start to dabble in other sizes and capacities and multi-cell/balanced configurations, the hobby charger starts to make more sense.


Re: Hobby Charger?
Written by DEERSLAYER on 01-09-2011 04:42 PM GMT

...october1 earlier had mused that the Accucel somehow looked safer than a Pila. Maybe this opinion was formed due to the Turnigy's LCD display or apparent "higher tech-i-ness" of the hobby charger as opposed to the Pila's purposefully simple face -- I'm really not sure what prompted that particular dotted line connection but it isn't the case at all.

I said that it seemed better, not "looked" better. I mostly based this on the ability to be calibrated and the programmability that allows you to set up the charger for a more gentle charging cycle as well as lowering the termination voltage a notch. Plus there are those pesky claims by Pila of "standby mode, trickle charging" and to only use it with their special batteries. I said that it seemed better, not "looked" better. I mostly based this on the ability to be calibrated and the programmability that allows you to set up the charger for a more gentle charging cycle as well as lowering the termination voltage a notch. Plus there are those pesky claims by Pila of "standby mode, trickle charging" and to only use it with their special batteries.

Unfortunately it appears as though I may have to stick to primary's because by the sounds of it I don't dare fall asleep while charging Lithium ions and I don't want to have to babysit the charger for hours because 95% of the time I would be using them during hunting season or fishing trips, in which case I would have very little idle time. It would take days to complete a charge during these trips if I had to always be present. Especially during hunting season where I often use my flashlight 2 (sometimes 4) hours a day walking deep into and out of the woods.


Re: Hobby Charger?
Written by LetThereBeLite on 01-09-2011 05:02 PM GMT

I said that it seemed better, not "looked" better. I mostly based this on the ability to be calibrated and the programmability that allows you to set up the charger for a more gentle charging cycle as well as lowering the termination voltage a notch. Plus there are those pesky claims by Pila of "standby mode, trickle charging" and to only use it with their special batteries.

That's right. The Pila chargers have the most draconian warranty disclaimers I've ever seen. According to the warranty, you can That's right. The Pila chargers have the most draconian warranty disclaimers I've ever seen. According to the warranty, you can ONLY use their batteries with their chargers, otherwise the warranty is invalidated. Almost no one here uses Pila Batteries with the Pila charger. I fully understand why Pila wants to disclaim/indemnify their liability for crappy li-ion batteries manufactured by other companies, but that doesn't change the fact that the charger has the most draconian warranty disclaimer I've ever seen.

Still, if someone were to send me a Pila charger gratis, I certainly wouldn't reject the charger. :)

I actually think the Hobby Chargers--given their displays with stats--are safer. If a Pila malfunctions, you won't know it until it's too late--the batteries have exploded. With a Hobby Charger, one can at least see the current voltage of the battery and the number of mahs already pumped into the battery. But a hobby charger does require one to know what one is doing. My mother or wife definitely would not benefit from a hobby charger. It definitely is more dangerous for them to be using a hobby charger to recharge li-ion cells. However, for me now, after having read up on hobby chargers, I think it is actually a safer charger because it has the stats to show me exactly what is happening to the batteries. Blind consumer chargers, e.g. Pila and XTAR WP2, have no displays to show any stats. Similarly in the NiMH world, I love the Maha C9000 and the La Crosse BC9009 because they have so much information displayed regarding the current batteries being charged. Likewise with the Hobby Chargers for li-ion cells. I need to see the stats to feel safer about the batteries being charged. Otherwise I'm blind as a bat.


Re: Hobby Charger?
Written by flatline on 01-09-2011 05:34 PM GMT

If you are willing to only get 18650's of 1500 mAh or greater capacity, a Pila charger will work well for you. As soon as you start to dabble in other sizes and capacities and multi-cell/balanced configurations, the hobby charger starts to make more sense.

1500? I was under the impression that the Pila charging current (600mA?) was fine for any cells greater than 600 mAh. 1500? I was under the impression that the Pila charging current (600mA?) was fine for any cells greater than 600 mAh.

--flatline


Re: Hobby Charger?
Written by KiwiMark on 01-09-2011 05:52 PM GMT

With a Hobby Charger, one can at least see the current voltage of the battery and the number of mahs already pumped into the battery. But a hobby charger does require one to know what one is doing.

However, for me now, after having read up on hobby chargers, I think it is actually a safer charger because it has the stats to show me exactly what is happening to the batteries.

There are other things that hobby chargers can do as well: There are other things that hobby chargers can do as well:

- Set a maximum time, where the charger will cut out if the charging time reaches that user set value.

- Set a maximum capacity, where the charger will cut out if the charging capacity reaches that user set value.

- Set a maximum temperature, where the charger will cut out if the battery temperature exceeds the user set value - this requires a thermal probe, but if you want this feature there are hobby chargers available that come with a thermal probe.

This is over and above the user having the ability to go over to the charger and take a look at what the display is reading.

I have done some charging & discharging with my Accucel-8 while it was connected to my laptop and with the thermal probe on the battery. From the readings that were logged to the computer and graphed I can see what temperature is 'normal' for a Li-ion cell during a charge - I can set the charger to cut off if the battery temperature exceed 5 degrees above that. This value can be used for all my batteries and is therefore easier than setting a time or capacity limit.

If you are charging a whole bunch of identical batteries then setting a capacity limit could prevent disaster if something is going wrong during the charging of one of them.

It is also worth noting that the hobby chargers definitely DO use a proper CC/CV charging algorithm and don't trickle the Li-ion batteries after the charge ends. This is stated in their manuals and can be verified by watching the display during charging. Even the $20 cheapies seem to do everything the right way. They can also be calibrated so you can fix the charger that keeps charging your Li-ion cells to 4.22 so that it will just charge to 4.20 - can the Pila (or any other cradle charger) do that?

With a little knowledge and care the hobbyist can use the hobby chargers VERY safely, while the careless will be better off with primaries or NiMH cells.


Re: Hobby Charger?
Written by hoongern on 01-09-2011 05:53 PM GMT

1500? I was under the impression that the Pila charging current (600mA?) was fine for any cells greater than 600 mAh.

--flatline

Charging currents depend on the specific cell being used - all cells have different maximum charging rates. For MOST [Lithium Cobalt] Li-Ions, charging currents should not exceed 0.7C, so for 600mA charge, that would work out to a 857mAh cell. Charging currents depend on the specific cell being used - all cells have different maximum charging rates. For MOST [Lithium Cobalt] Li-Ions, charging currents should not exceed 0.7C, so for 600mA charge, that would work out to a 857mAh cell.

However, it's recommended to normally charge < 0.5C for cell longevity, so that would mean a 1200mAh cell.

As a reminder, always refer to specific cell specifications for their maximum charging rates! A good example is the following: Panasonic NCR18650 2900mAh should only be charged with 825mA (0.3C)!! Meanwhile, AW IMR18650 (1600mAh) can be charged at a maximum (but not necessarily recommended) of 4.5A (2.8C)!!

That's the beauty of a hobby charger - it's versatility... Or, from another point of view - the Pila, which can ONLY be used for cells which can be charged at 600mA or higher, but for those cells, does it well.


Re: Hobby Charger?
Written by LetThereBeLite on 01-09-2011 06:02 PM GMT

Yep, all very good points, of which I am now fully aware after having done quite a bit of reading on hobby chargers. I can now fully appreciate all the safety features built into hobby chargers. But Tandem does make a good point. If someone not too familiar with hobby chargers accidentally charges a li-ion cell by hitting the Pb (lead acid) option, that could be pretty dangerous. So hobby chargers are meant for a certain demographics. I'm happy to now consider myself a part of that demographics. :)

There are other things that hobby chargers can do as well:
- Set a maximum time, where the charger will cut out if the charging time reaches that user set value.

- Set a maximum capacity, where the charger will cut out if the charging capacity reaches that user set value.

- Set a maximum temperature, where the charger will cut out if the battery temperature exceeds the user set value - this requires a thermal probe, but if you want this feature there are hobby chargers available that come with a thermal probe.

This is over and above the user having the ability to go over to the charger and take a look at what the display is reading.

I have done some charging & discharging with my Accucel-8 while it was connected to my laptop and with the thermal probe on the battery. From the readings that were logged to the computer and graphed I can see what temperature is 'normal' for a Li-ion cell during a charge - I can set the charger to cut off if the battery temperature exceed 5 degrees above that. This value can be used for all my batteries and is therefore easier than setting a time or capacity limit.

If you are charging a whole bunch of identical batteries then setting a capacity limit could prevent disaster if something is going wrong during the charging of one of them.

It is also worth noting that the hobby chargers definitely DO use a proper CC/CV charging algorithm and don't trickle the Li-ion batteries after the charge ends. This is stated in their manuals and can be verified by watching the display during charging. Even the $20 cheapies seem to do everything the right way. They can also be calibrated so you can fix the charger that keeps charging your Li-ion cells to 4.22 so that it will just charge to 4.20 - can the Pila (or any other cradle charger) do that?

With a little knowledge and care the hobbyist can use the hobby chargers VERY safely, while the careless will be better off with primaries or NiMH cells.

Re: Hobby Charger?
Written by DEERSLAYER on 01-09-2011 07:57 PM GMT

There are other things that hobby chargers can do as well:

- Set a maximum time, where the charger will cut out if the charging time reaches that user set value.

- Set a maximum capacity, where the charger will cut out if the charging capacity reaches that user set value.

- Set a maximum temperature, where the charger will cut out if the battery temperature exceeds the user set value - this requires a thermal probe, but if you want this feature there are hobby chargers available that come with a thermal probe...

Thanks for that post. I suspected the first one (timer), but was unaware the other two were available. I would probably use all three. Thanks for that post. I suspected the first one (timer), but was unaware the other two were available. I would probably use all three. :thumbsup:

 

[tandem]

Re: Hobby Charger?
Written by tandem on 01-09-2011 08:31 PM GMT

I said that it seemed better, not "looked" better.

Looked, seemed -- "get the impression" were your actual words -- I think we are on the same page. I simply wanted to correct your impression or perhaps more pointedly wanted to ensure that your impression didn't leave an incorrect impression in the minds of other readers of this thread in the future. Looked, seemed -- "get the impression" were your actual words -- I think we are on the same page. I simply wanted to correct your impression or perhaps more pointedly wanted to ensure that your impression didn't leave an incorrect impression in the minds of other readers of this thread in the future.

I mostly based this on the ability to be calibrated and the programmability that allows you to set up the charger for a more gentle charging cycle as well as lowering the termination voltage a notch.

Depending on the cells you are charging this might indeed sway one to a hobby charger. Small in capacity cells (< 600 mAh) ought not be charged in the Pila. But that isn't a fault of the Pila IBC charger - used as intended, for the type of cells it is designed for, it is a safe and well built charger. Depending on the cells you are charging this might indeed sway one to a hobby charger. Small in capacity cells (< 600 mAh) ought not be charged in the Pila. But that isn't a fault of the Pila IBC charger - used as intended, for the type of cells it is designed for, it is a safe and well built charger.

Plus there are those pesky claims by Pila of "standby mode, trickle charging" and to only use it with their special batteries.

FYI -- the Pila FYI -- the Pila does not trickle charge. This is well documented here at CPF. They had made an unfortunate choice of words in their documentation. The Pila terminates properly unlike so many others.

Their warranty might cause some an issue, as making the use of their own cells as something of a shield against warranty claims isn't right in my opinion either. But for a cradle style charger, it is what it is. At the time I bought mine there wasn't another cradle style 2 bay charger out there that could say it was as reliable and as field proven as the Pila. That is worth more to me than is taken away by the specious warranty verbiage put out by the company.

Unfortunately it appears as though I may have to stick to primary's because by the sounds of it I don't dare fall asleep while charging Lithium ions and I don't want to have to babysit the charger for hours because 95% of the time I would be using them during hunting season or fishing trips, in which case I would have very little idle time. It would take days to complete a charge during these trips if I had to always be present. Especially during hunting season where I often use my flashlight 2 (sometimes 4) hours a day walking deep into and out of the woods.

Among the safety geeks here (guilty I am) and also on RC sites like rcgroups.com you'll consistently hear the advice that you should not leave your lithium cells charging unattended. It only makes sense given the potential for issues. Among the safety geeks here (guilty I am) and also on RC sites like rcgroups.com you'll consistently hear the advice that you should not leave your lithium cells charging unattended. It only makes sense given the potential for issues.

While li-ion fires are not common, they do happen. They seem to happen more frequently in the Remote Control hobby - that is likely due to the increased occurrence of cell damage (think crashing planes and such) and probably has something to do with how hard they push their cells. Quality of cells might in some cases have a bearing on failures too. We have that issue here in flashlight land.

Flashlights are tools and some folks aren't gentle with them. Maybe your light won't ever fall 6 or 30 or 80 feet and land on its longitudinal access and cause some internal damage to the cell which isn't obvious when slapping the cell in the charger next time, but maybe it will. Some of our high power lights push cells pretty hard too. Some cells are not built well. Given the potential for serious failure, even if the potential is minute, in my opinion it makes sense to raise a flag of caution.

Perhaps I'm overly cautious? I don't think so, but I could be more of a safety geek than most due to the victim assistance work I do with our fire department. I pay very close attention to causes of fires. When laptop and other electronic device makers started having issues with cells going into thermal runaway causing fires it caught my attention... before this work I was a long time laptop user and I'd fallen asleep countless times with my laptop on a couch or on my hotel room bed while travelling. No more after learning of laptop pack caused fires. Most name brand laptops have good quality cells and well engineered charging systems yet incidents occurred.

Over the last several years in my city we've had dozens of fires traced to electrical issues but only one lithium ion caused fire. It was a laptop that was left running on a couch. This fire caused a fatality. I don't know the brand of laptop.

What an incident like that informs me is that I don't really want to leave a li-ion cell charging when I'm not around nor when I'm asleep. I can manage the risk by purchasing good equipment and good cells and further manage and reduce the risk of an incident getting out of control by being there.

I doubt I'll ever see a lithium ion cell burst or go into thermal runaway, but I still act as if it could happen tomorrow. It takes no real effort to be careful much like driving safely for most of us becomes second nature.

Does it take a lot of time to be around for charging?

I find it takes 3 - 4 hours to charge (with a 600 mA Pila) a large capacity 18650 cell (2900 mAh) that has been fairly completely drained but not over-discharged. A hobby charger could possibly do the job a little faster with a higher current charge rate (kept within reason). You can easily find lights that will put out a decent amount of light for 2 - 4 hours off a single cell, or abundant light for 2 hours off a single cell. If you have a collection of 4 cells, maybe even just 2 depending on your use of different output levels, chances are you can easily stay ahead of the game.


Re: Hobby Charger?
Written by flatline on 01-09-2011 10:39 PM GMT

Charging currents depend on the specific cell being used - all cells have different maximum charging rates. For MOST [Lithium Cobalt] Li-Ions, charging currents should not exceed 0.7C, so for 600mA charge, that would work out to a 857mAh cell.

However, it's recommended to normally charge < 0.5C for cell longevity, so that would mean a 1200mAh cell.

As a reminder, always refer to specific cell specifications for their maximum charging rates! A good example is the following: Panasonic NCR18650 2900mAh should only be charged with 825mA (0.3C)!! Meanwhile, AW IMR18650 (1600mAh) can be charged at a maximum (but not necessarily recommended) of 4.5A (2.8C)!!

That's the beauty of a hobby charger - it's versatility... Or, from another point of view - the Pila, which can ONLY be used for cells which can be charged at 600mA or higher, but for those cells, does it well.

Maybe I'm remembering incorrectly, but I thought it was safe to charge at 1C (at the expense of cell longevity, perhaps). Battery University seems to agree. Maybe I'm remembering incorrectly, but I thought it was safe to charge at 1C (at the expense of cell longevity, perhaps). Battery University seems to agree.

I don't particularly care about cell longevity, but I care mightily about safety. If charging my 750 mAh AW RCR123 cells in the Pila charger can lead to unsafe cells, I'd sure like to know about it.

--flatline


Re: Hobby Charger?
Written by hoongern on 01-09-2011 11:41 PM GMT

Maybe I'm remembering incorrectly, but I thought it was safe to charge at 1C (at the expense of cell longevity, perhaps). Battery University seems to agree.

Battery University agrees and disagrees. Battery University agrees and disagrees.

1) It gives general guidelines, but if a cell manufacturer specifies a maximum/recommended charge current - that information should always be taken at a higher priority. If information for a particular cell is not provided, it is safer to assume a lower maximum, however, one could use a 1C charge which may not pose a problem.

2) However, the charging time difference between 0.5C and 1C charging is minuscule (because of the CV stage), but 0.5C treats the cells more gently.

3) BU says the following statements:

- "The charge time of most chargers is about 3 hours. Smaller batteries used for cell phones can be charged at 1C; the larger 18650 cell used for laptops should be charged at 0.8C or less."

--> Less is always better. Some cells can be charged at 1C (with hardly any benefits), but others can't. If the manufacturer says it can, go ahead. If information isn't provided, then who knows?

- "The charge current of Li-ion should be moderate (0.5C for cobalt-based lithium-ion)."

--> For best results

In all likeliness, you probably won't face any problems. I've never heard of issues with the AW16340 and Pila - but it is arguably not charging it at optimum rates. So go ahead if you already have the combination, but whenever I give advice to Li-Ion users, for safety and correctness, I generally recommend 0.5C or less, and to check with the manufacturer for charging specifications.

Of course, LiFePO4, LiMn, etc. have differences.


Re: Hobby Charger?
Written by flatline on 01-10-2011 04:36 AM GMT

In all likeliness, you probably won't face any problems. I've never heard of issues with the AW16340 and Pila - but it is arguably not charging it at optimum rates. So go ahead if you already have the combination, but whenever I give advice to Li-Ion users, for safety and correctness, I generally recommend 0.5C or less, and to check with the manufacturer for charging specifications.

Are the manufacturer charging specifications published for the AW 16340? I was unable to find anything, but my google-fu is weak. Are the manufacturer charging specifications published for the AW 16340? I was unable to find anything, but my google-fu is weak.

If 600mA really is too much for the RCR123, short of buying a new charger, what options do I have?

I know I could charge 2 cells in parallel (resulting in .4C charge rate for both rather than the .8C charge rate when charging them normally). But I only have 2 RCR123 cells, so that would be inconvenient.

If I rigged up a simple current divider with, say, a 15-ohm resistor in parallel to the cell, would that interfere with the operation of the Pila? Naively, it seems like the CC portion of the charging procedure would be fine, but the CV portion would probably never terminate.

Perhaps when my current 2 RCR123 cells die, I'll just replace them with IMR cells (trade a little capacity for the ability to safely charge at 600mA).

--flatline


Re: Hobby Charger?
Written by 45/70 on 01-10-2011 09:48 AM GMT

Just to add a bit,most LiCo Li-Ion cells smaller than 18650 size are spec'd for charging at a maximum of 1.0C. I say "most", because there may be some 17650, 18500, and similar cells that are an exception. All of the specs I've ever seen for the smaller LiCo cells (14250, 15266, 16340, etc.) however, are spec'd at 1.0C max though.

Dave


Re: Hobby Charger?
Written by tandem on 01-10-2011 10:47 AM GMT

If the specs published by Battery Junction are correct. it looks like all the UF 18650 cells have a max charge spec of 0.5C, not that I trust Ultrafire cells or specifications.

Samsung publishes a 1C rate for their ICR18650B3 cell sold by Battery Junction. Panasonic seems to suggest 0.7C but the way that is written I wonder if that is a best practice recommendation rather than a hard max guideline.


Re: Hobby Charger?
Written by hoongern on 01-10-2011 04:58 PM GMT

Are the manufacturer charging specifications published for the AW 16340? I was unable to find anything, but my google-fu is weak.

If 600mA really is too much for the RCR123, short of buying a new charger, what options do I have?

I know I could charge 2 cells in parallel (resulting in .4C charge rate for both rather than the .8C charge rate when charging them normally). But I only have 2 RCR123 cells, so that would be inconvenient.

If I rigged up a simple current divider with, say, a 15-ohm resistor in parallel to the cell, would that interfere with the operation of the Pila? Naively, it seems like the CC portion of the charging procedure would be fine, but the CV portion would probably never terminate.

Perhaps when my current 2 RCR123 cells die, I'll just replace them with IMR cells (trade a little capacity for the ability to safely charge at 600mA).

--flatline

Hmm. We seem a bit off topic from the initial hobby chargers... But I'd say - I wouldn't really worry about your setup. The cells may just not last as long. You can always ask AW, of course. Hmm. We seem a bit off topic from the initial hobby chargers... But I'd say - I wouldn't really worry about your setup. The cells may just not last as long. You can always ask AW, of course.

My 0.5C advice is more for people who are using hobby chargers, or are going to be buying a new charger and are wondering what rate to charge at.

Just on another note, related to charging safely, for those of you who have hobby chargers, most of them do support voltage calibration, which you should do if possible, so that you know you're charging accurately! Hopefully you can find/borrow/use either a proper DMM (Like a Fluke) or good Oscilloscope, or a VERY accurate power supply.


Re: Hobby Charger?
Written by radellaf on 01-10-2011 05:51 PM GMT

I used a LT1009 for calibration, and my two voltmeters read 2.50 and 2.51V, so good enough I'd say.

I have been worrying a bit about my Ultrafire RCR123 as it tests at about 600mAh and my two chargers are 500mA (Xtar MP1 w/spacer) and 420mA (cottonpickers smallest charger). Probably best off with my 3.0/3.6 switchable WF-138 (250mA) that I've tested to cut off properly.

BUT...back to topic.

I'd like to get a hobby charger, but since I'd like a good one, any opinions on Bantam's cheaper 301DX-II version? It's $60-$80, less than the Turnigy Accucell equivalent BC6, but seems to do everything I need, is smaller, and here's the huge plus, it appears to be heatsinked to the case and has no fan.

Anyone use one?

Figured I might pair it with a Mastech 1505D 0-15V 5A CC/CV bench power supply, which would be generally useful for all sorts of things, like seeing what voltage a flashlight goes out of regulation, testing emitter If/Vf, etc.


Re: Hobby Charger?
Written by kaptain_zero on 01-10-2011 07:50 PM GMT

I had a quick look at the manual/specs and it's pretty much identical to a Turnigy accucell 6 in specs (no surprise there, as most of these chargers are copies of each other), as in it's a 50w charge/ 5w discharge unit. It has a similar, if not the same firmware, display and button layout. For the record, there are users of the Accucell 6 who are using them without the fan hooked up as it appears it's not really needed. I lubed up both my units as soon as I got them and they are nice and quiet. I got my two Accucell 6 chargers for less than $60 total so as far as I can see, I got the better deal. A step up would be the HobbyKing ECO6-10 200W 10A, at around $35 + shipping. It has a much greater capacity at 200w vs 50w but if you are charging batteries one at a time, the 50w chargers are more than enough. RCgroups has a loooong thread on the Accucell 6 and they touch on quite a few other chargers. Those guys really wring every last mAh out of everything so if it works for them, it'll work for us. Good place to find info.

That Mastech is nice, but it's gross overkill for charging.... I use a converted ATX computer power supply for my 2 Turnigy chargers and it runs both with power to spare and was *free*. But hey, it's your $$$ and you can spend them as you like. I'd love to buy one of those Mastech supplies myself, but mostly for powering up my own home made/designed electronics for testing purposes.

Regards

Christian

I'd like to get a hobby charger, but since I'd like a good one, any opinions on Bantam's cheaper 301DX-II version? It's $60-$80, less than the Turnigy Accucell equivalent BC6, but seems to do everything I need, is smaller, and here's the huge plus, it appears to be heatsinked to the case and has no fan.

Anyone use one?

Figured I might pair it with a Mastech 1505D 0-15V 5A CC/CV bench power supply, which would be generally useful for all sorts of things, like seeing what voltage a flashlight goes out of regulation, testing emitter If/Vf, etc.

Re: Hobby Charger?
Written by radellaf on 01-10-2011 08:25 PM GMT

It may be there's really no advantage with going with the "original" Bantam brand, but as that model just looks so nice, I thought I'd ask.

Oh, I know the Mastech is overkill, but I don't have access to a lab right now and the number of times I've wished I had a nice CC-capable adjustable power supply around has become large enough that it's tempting to just spend the $100 or so and get one. $30 less and I could have a 15V 3A version, but the extra amps could be useful. Doubt I'd ever want the 30V 5A, though. Anyway, since I want one anyway, might as well use it to power the hobby charger. Less likely to go "poof" than the bricks. A computer supply is great but they add even more fan noise to the room. Which I suppose is no big deal if it's the same room with a desktop pc ;)

Re: Hobby Charger?
Written by BVH on 01-11-2011 08:53 AM GMT

Figured I might pair it with a Mastech 1505D 0-15V 5A CC/CV bench power supply, which would be generally useful for all sorts of things, like seeing what voltage a flashlight goes out of regulation, testing emitter If/Vf, etc.

I use a Mastech 30V 50 Amp PS and love it. I went that large because I use it to run my Locators - 28V, 16 running Amps. If you use a regulated, variable PS, don't forget to install a Schottky Diode in the + output cable to prevent spike/backflow of power to the PS which fried my first Mastech. I use a Mastech 30V 50 Amp PS and love it. I went that large because I use it to run my Locators - 28V, 16 running Amps. If you use a regulated, variable PS, don't forget to install a Schottky Diode in the + output cable to prevent spike/backflow of power to the PS which fried my first Mastech.


Re: Hobby Charger?
Written by KiwiMark on 01-11-2011 01:43 PM GMT

I totally messed up and damaged the circuitry on my Accucell-6 (I can't blame the charger) so I am now thinking of buying an iCharger 106B+ as this looks really good. It is quite a bit dearer than buying another Accucell-6 but it also looks to have better specs and a few better features. My Accucell-8 is still going strong and covers my occasional need to charge a set of 8 Li-ion cells, so the 106B+ has high enough specs for anything I am likely to need to do.

If the Bantam chargers are the original hobby chargers that all others are copied from then I would say that the iCharger looks to be the highest quality of the copies and from what I can tell they are highly thought of in the RC hobby community. They actually seem to be well priced for the specs compared to the Bantam chargers and dearer but not unreasonable compared to the cheapies.

I'd be happy with buying another Accucell-6 for the most part and they are really well priced for how well they work (given a lube or disconnect of the fan) but I would like to try out an iCharger to see how good they really are. I'd still recommend the Accucell-6 for anyone not wanting to spend too much but wanting a very capable & reliable charger, as long as their needs are within the limitations of course. (Charging: 50W, 6A, 6S cells. Discharging: 1A, 5W, 6S)

Not everyone plays around with some of the stuff that I do like my 212W hotwire flashlight, so not everyone will feel the need for more than 6A/50W charge or for 1A/5W discharge or for than 6S cells. Compared to any cradle charger I've seen the Accucell-6 absolutely blows them all away!

The 106B+ has some seriously nice specs - given the limit of 6S Li-ion charging, everything else is great. Up to 10A charging and up to 250W - that should be more then enough for any charging requirement I am likely to have for years to come. Up to 7A discharging amps and up to 20W should allow for some decent battery testing (the Accucell-6 only discharges up to 1A and up to 5W). I haven't yet needed to charge a lead acid battery but I do like the 2-24V capability of the 106B+ better than the 2-20V for the Accucell-6 - most lead acid batteries I've seen are 6V or 12V or 24V and the Accucell-6 can only charge the first 2 while the 106B+ can charge all 3.


Re: Hobby Charger?
Written by HKJ on 01-11-2011 02:07 PM GMT

I have been using the iCharger for some time and like it. One of the great thing with it is software updates, if a bug is found a new software version is made to fix it.

It is definitely not a copy of the other hobby chargers, but the original iCharger was probably inspired by the standard hobby charger format and function.


Re: Hobby Charger?
Written by radellaf on 01-11-2011 02:40 PM GMT

"spike/backflow"? Is this something that would happen charging a string of NiMH or a single 18650 with a bantam (or similar), or were you doing something else with it?

I've been playing with electronics for 27 years now and always wanted an adjustable current limited supply, so I'll get at least the HY1503D (15V 3A) for $70 (shipped, direct from Mastech) sometime soon. If it lasts, I'm sure I'll still be using it 27 years hence. Should be good for analyzing SST-50, MCE, and XM-L lights, though I'm sure someone will be pushing the XM-L past 3A before long.

I have a 12V 30A Pyramid from back in my ham radio days, but in addition to being 20 years old (think of the state of the electrolytics), I can't find it any more... Fun thing there was that when I installed a wire to run a backlight in an antenna matcher, the RF coming back to the PS on that lead caused it to de-regulate up to 18V. Lucky I was using a radio that was made for automotive use, as I assume their accounting for 18V "load dumps" in a car is why it survived years of operating that way.

Anyway, decision made, I just ordered a Bantam e-stationBC-6 BC6DX-II AC/DC for $158 shipped, with temp probe and USB connection kit from RC Accessory. Ouch! It's the least expensive one with that nice large display, and ability to use a temp probe simultaneously with USB is great. I'm mostly a Mac guy, so it'll be nice to be able to view simple graphs on the screen without having to boot into XP. But, doesn't need a power supply. The Mastech had a fan, anyway, so even with the 301dx-ii, no way around it I suppose.

Also, this may be worth noting for some of you cutting edge LiIon people. That charger allows you to Manually Set Termination Voltage. So if I want to play with oddball hi capacity cells that need 4.35 charge, I'm set.

c.f.: http://www.candlepowerforums.com/vb/...d.php?t=275159

Re: Hobby Charger?
Written by KiwiMark on 01-11-2011 04:16 PM GMT

I have been using the iCharger for some time and like it.

Is it the 106B+ or one of the other models? Some of the higher models look pretty good with support for 8S Li-ion cells and 20A or even 30A charging current, but I just don't see myself needing anything like that. I only have one 8S Li-ion pack and with an Accucell-8 already that can handle charging that pack I can't see what I'll ever need more than the 106B+ for. Is it the 106B+ or one of the other models? Some of the higher models look pretty good with support for 8S Li-ion cells and 20A or even 30A charging current, but I just don't see myself needing anything like that. I only have one 8S Li-ion pack and with an Accucell-8 already that can handle charging that pack I can't see what I'll ever need more than the 106B+ for.

The 106B+ is $80 + shipping from HobbyKing which is quite a bit more than the $23 + shipping for the Accucell-6, but we are talking about a 250W charger instead of a 50W charger so you have to expect to pay more. $80 isn't cheap, but it isn't horribly expensive - I've paid over that for a single flashlight more than once. The 106B+ also comes with thermal probe and USB communication so those features have to be worth some extra money too.

Anyway, decision made, I just ordered a Bantam e-stationBC-6 BC6DX-II AC/DC for $158 shipped, with temp probe and USB connection kit from RC Accessory. Ouch!

Hmmm, that seems like quite a bit of money. I don't really see what it offers compared to the 106B+ except for the built in power supply. I guess it comes down to whether you want to pay more for a Bantam charger and how much you value the convenience of a built in power supply. On my charging bench I have a computer power supply that I didn't have to go out and buy and it easily provides enough power to run two hobby chargers - so I guess I don't value a built in power supply very highly. I can imagine plenty of situations where the built in power supply could be very worthwhile though. Hmmm, that seems like quite a bit of money. I don't really see what it offers compared to the 106B+ except for the built in power supply. I guess it comes down to whether you want to pay more for a Bantam charger and how much you value the convenience of a built in power supply. On my charging bench I have a computer power supply that I didn't have to go out and buy and it easily provides enough power to run two hobby chargers - so I guess I don't value a built in power supply very highly. I can imagine plenty of situations where the built in power supply could be very worthwhile though.

I think that hobby chargers are great and it is fantastic that you can buy something worthwhile for $23 or spend more to have whatever features & specs you want. You can spend under twenty bucks or you can spent over $300 - and that sort of choice is just what you want to see. Not everyone can afford to spend over a hundred bucks on a charger and I think the Accucell-6 would be a great choice on a tight budget. Some people can afford to buy whichever charger they really want, so why shouldn't they?

I would like to suggest that from what I've read up on hobby chargers and from my own experience the best buys seem to be:

Budget charger:

Accucell-6 - Limited to 6A/50W charge, 1A/5W discharge & 6S

or Accucell-8 - MUCH higher limits with 7A/150W charge, 5A/25W discharge & 8S (great if you need to charge 8 cells in series or more than 50W or test cells at a higher discharge rate)

Mid to high price charger:

iCharger & Bantam - whichever model suits your price/performance needs.

^This info is probably what a newby needs to know when buying a hobby charger.


Re: Hobby Charger?
Written by KiwiMark on 01-11-2011 04:21 PM GMT

I recently learned that a 'hobby charger' can charge all of the types that I am looking for - 10440, 14500, rcr123, 18650, and even eneloops (!!!). However, I am a bit out of my league with all of this magnets, balancing, DIY cradles and such. I don't want to pay a lot (under $50 would be good, closer to $20 would be ideal if such a thing is possible). I don't mind some learning curve. I probably wouldn't charge more than one cell at a time, and I can't imagine being motivated enough to make a DIY cradle. I am not too experienced with soldering, though I'm sure could manage something simple if I needed to.

Please advise? Is there a product out there for me that won't require me to be an electrician? :nana:

For the OP and anyone else starting out: For the OP and anyone else starting out:

Try this and this as a starter setup without costing a fortune. It should cost less than $50 with shipping and give you what you need to do everything that you have said you want to do.

Generally if you are only charging one cell at a time the 6A and 50W charging limits are not going to be an issue, 4.2V at 6A is only 25W which wont be a problem to the power supply or charger so you can freely charge any battery up to 6 amps - I doubt that you'll find yourself needing to exceed that.

I generally just half the capacity and charge at that amount i.e. 2200mAh 18650 = charge at 1100mA (1.1A), 2800mAh 18650 cell - charge at 1.4A, 750mAh 14500 or RCR123 = charge at 0.3A (I prefer to round down), 250mAh 10440 cell = charge at 0.1A (rounded down again).

When you turn the charger on it remembers the last setting - if it is set for LiPo (4.2V charge limit) and 1.1A then you press 'start' then up/down to change the charge rate then hold 'start' button until it starts charging, most of the time that is all you need to do. You don't need to press the buttons hundreds of times and go through dozens of menus, mostly you are just using the last settings or maybe changing the charge rate to suit your 14500 cell instead of the 18650 you charged before it. You should always at least check the charge rate to ensure it matches what you should be using for the battery you just connected. Every time you go to charge a battery the number of cells & charging amps are clearly displayed on the screen - just look at the info and decide if it is what you want, it's pretty easy.

 

[tandem]

Re: Hobby Charger?
Written by BVH on 01-11-2011 05:32 PM GMT

If memory serves me, in my early days, I typically powered things by simply touching wires. I believe I was energizing an HID ballast, the wires slipped off and back on a few times and then "poof", Mr. Mastec died. I tried, with the help of a member here, to replace the 6 FET's but that didn't work. Better to be safe than sorry.

Re: Hobby Charger?
Written by radellaf on 01-11-2011 08:44 PM GMT

Hmmm, that seems like quite a bit of money. I don't really see what it offers compared to the 106B+ except for the built in power supply. I guess it comes down to whether you want to pay more for a Bantam charger and how much you value the convenience of a built in power supply.

Well it has the bigger screen that can show the graphs (and other fun stuff I imagine) is one thing. I am, perhaps without proof, thinking the Bantam name is worth something in terms of reduced chance it will have a (possibly destructive) failure, and, the power supply is a (very) nice extra. But the screen is worth a lot IMHO. And for NiMH I do want USB and temp probe both usable at the same time. 250W would be nice but I don't think I need that right now. Well it has the bigger screen that can show the graphs (and other fun stuff I imagine) is one thing. I am, perhaps without proof, thinking the Bantam name is worth something in terms of reduced chance it will have a (possibly destructive) failure, and, the power supply is a (very) nice extra. But the screen is worth a lot IMHO. And for NiMH I do want USB and temp probe both usable at the same time. 250W would be nice but I don't think I need that right now.

So, let it never be said that I'm _saving money_ using rechargeables instead of primaries. ;)

I'll certainly grant that the $30 (+20s/h) hobby chargers are a surer bet than the cheap "cradle" chargers. A hobby charger might fail, but the others seem largely bad by design. I don't know that I can _really_ afford over $100, but as someone who enjoys analyzing batteries as much or more than using flashlights, I'll go ahead and spring for it.

---

Is a HID ballast something like a big inductor? That could easily generate kilovolts that could arc over when you opened the connection.


Re: Hobby Charger?
Written by BVH on 01-11-2011 10:09 PM GMT

Is a HID ballast something like a big inductor? That could easily generate kilovolts that could arc over when you opened the connection. Dunno if a diode would have a high enough PIV, might need a MOV or something ;)

Some call it an inverter, some a transformer, but not really being an electronics expert, I use the familiar term, ballast. The primary side of a typical ballast can see anywhere from 9 to 18V DC and the secondary side outputs somewhere around 23 to 25KVAC for a microsecond. The Schottky that was recommended IIRC, is 100 Amp, 50V or there-abouts. Some call it an inverter, some a transformer, but not really being an electronics expert, I use the familiar term, ballast. The primary side of a typical ballast can see anywhere from 9 to 18V DC and the secondary side outputs somewhere around 23 to 25KVAC for a microsecond. The Schottky that was recommended IIRC, is 100 Amp, 50V or there-abouts.


Re: Hobby Charger?
Written by radellaf on 01-11-2011 10:31 PM GMT

Google gets me a schematic pretty easily:
http://wvsp.tripod.com/light1.html

Input isn't direct to the transformer, but close enough I imagine you could get a spark.

I'd be a lot happier with a shunt Zener diode like a 1N5359 (plus perhaps a 50V MOV), than a series schottky, as once the breakdown of the series diode is exceeded, it's just going to conduct the surge. 'course, anything would help, and I'm not sure how high a surge the power supply can take without damage.

Anyway, point taken, if I power up any inductive loads beyond a small CCFL backlight inverter, I'll take precautions.


Re: Hobby Charger?
Written by HKJ on 01-11-2011 10:59 PM GMT

Is it the 106B+ or one of the other models?

It is a 208B, I wanted the build in logging function. I have later found out that the measuring precision of the iCharger is low at lower currents. It is a 208B, I wanted the build in logging function. I have later found out that the measuring precision of the iCharger is low at lower currents.


Re: Hobby Charger?
Written by tandem on 01-11-2011 11:03 PM GMT

... from back in my ham radio days

I wonder how many of us there are here. I'm a VE7. I wonder how many of us there are here. I'm a VE7.

The 106B+ has some seriously nice specs - given the limit of 6S Li-ion charging, everything else is great. Up to 10A charging and up to 250W - that should be more then enough for any charging requirement I am likely to have for years to come. Up to 7A discharging amps and up to 20W should allow for some decent battery testing (the Accucell-6 only discharges up to 1A and up to 5W).

Discharge capability is one of the main reasons why I'm looking into these in the first place. Outgrowing the Accucell 6 in this regard wouldn't be too hard and I like user-updatable firmware in the iChargers. Discharge capability is one of the main reasons why I'm looking into these in the first place. Outgrowing the Accucell 6 in this regard wouldn't be too hard and I like user-updatable firmware in the iChargers.

Too bad the FMA Multi4 doesn't have a discharge function; to get this capability you have to either go with their chemistry limited CellPro chargers or their new flagship the Powerlab 8.

However for someone that wants to use a computer more often than not to control the charger, and be able to tune almost any parameter, the Multi4 (and presumably the more expensive and more capable Powerlab) looks like it offers a lot. ~ 55 bucks but requires you spend another 15 - 20 bucks on a computer interface which is somewhat disingenuous for a charger that can only be fully controlled by a computer.

I'm not into RC but might be tempted one year. The Powerlab 8 seems way overkill unless one is flying some big aircraft and often. $250.

It can discharge up to 10A though, and up to 40A into a lead acid battery. ;0


Re: Hobby Charger ?
Written by psdx on 01-13-2011 01:26 PM GMT

+1 for thehobby charger solution. Any of the hobby chargers will give you temperature, time and voltage limits to protect each cell individually. Every one I've seen periodically checks the cells for their state of charge to determine what's next. Mine assesses the state of charge every 60 seconds by stopping the charge current momentarily to momentarily sample each cell's voltage and adjusts the charge current to each cell accordingly. The volt meter in the charger displays to the 1/1000 of a volt and attempts to bring them all to exactly 4.2 (or 4.1) volts. There's a thread in the marketplace that has 18650 holders for sale. Mine's not pretty, but it works very well. Also below is a sample output chart showing the voltage & current for a single cell (to keep it from being too busy). The x-axis is in seconds.

Re: Hobby Charger ?
Written by radellaf on 01-16-2011 09:26 PM GMT

http://www.flickr.com/photos/radell...ickr.com/5243/5362780462_5107e0bf66.jpg[/img]

The big screen is very nice, and I do like the built in power supply.

But, for the money, I am a little disappointed that it can't store data for transfer to the computer later, and that it communicates through a 1980s style serial connection I could have used with a TRS-80 instead of having a powerful enough processor to do more extensive USB communications. i.e., mount as a mass storage device with log files that can be copied off of it.

Also, it's not very configurable IMHO. A lot of options, but a lot less than I hoped, including no ability to manually set charging termination voltage. It's just not the CBA, UBA or Schulze that I think should be available in this price range. Or even just a neat geek-friendly gadget. The interface is just so... archaic.

The alarm on it is very loud and not adjustable. Just has options for off, or 5 annoying "melodies". A simple lower pitched tone would be nice, as would a volume control.

And, the permanently attached DC-in alligator clips are entirely out of place on a AC/DC charger. I'll probably cut them off, leave a few inches, and put on a male Molex 1545 (RS 274-222 is the ham radio standard). They aren't a safety problem, though. I checked with the dealer and if it's running off AC and you short the DC input, it will stop, but no spark and nothing gets damaged. Other good thing is that the mini fan is quiet, and doesn't always come on (like for low rate charging).

All things considered, it is a HUGE upgrade from my MAHA C777PLUS-II and the first LiIon charger I have that I feel I can really trust. Somehow, I'm both a little disappointed, and yet feel it was money well spent. The extra for the name-brand peace-of-mind also got me the big screen, and that makes it much more fun to use.


Re: Hobby Charger ?
Written by clintb on 01-17-2011 08:59 AM GMT

FMA PL8 battery workstation for me! Notice "workstation", and that's because this sucker will do whatever you want it to, and all can be controlled directly from your PC via the Charge Control Software (CCS). After the FMA announcement of this last year (one year, to be exact), I sold my other hobby chargers and jumped for the PL8.

Specs:

1344 W charge (40 A)

100 w discharge

8S Lithium

21 cells Nixx

Features:

Works on a preset system that can be completely generated on your PC through the CCS, then uploaded to the charger. Control every parameter of charging/discharging/cycling/monitoring. Don't like beeps on completion...turn it off. Don't like the beeps to be super loud...turn it down.

The PL8 isn't cheap, but the likelihood of needing to replace this thing in the near future is very, very low.

Revolectrix/FMA PL8

Re: Hobby Charger ?
Written by BVH on 01-17-2011 09:41 AM GMT

FMA PL8 battery workstation for me! Notice "workstation", and that's because this sucker will do whatever you want it to, and all can be controlled directly from your PC via the Charge Control Software (CCS). After the FMA announcement of this last year (one year, to be exact), I sold my other hobby chargers and jumped for the PL8.

Specs:

1344 W charge (40 A)

100 w discharge

8S Lithium

21 cells Nixx

Features:

Works on a preset system that can be completely generated on your PC through the CCS, then uploaded to the charger. Control every parameter of charging/discharging/cycling/monitoring. Don't like beeps on completion...turn it off. Don't like the beeps to be super loud...turn it down.

The PL8 isn't cheap, but the likelihood of needing to replace this thing in the near future is very, very low.

Revolectrix/FMA PL8

Clinth, I read a few dozen pages of a huge RC group thread on this and came away with "my" understanding that for safety reasons, when using this Clinth, I read a few dozen pages of a huge RC group thread on this and came away with "my" understanding that for safety reasons, when using this charger in a manual and non-balancing mode, that it is limited to a two Amp charge rate. Then someone in the know on that thread replied and I didn't quite understand the reply but I think he was trying to tell me otherwise. Can you tell me if this charger can do manual - non balancing charging at any rate I choose? Are there any programatic restrictions on its use? From the specs, it seems like a fantastic charger and I'd thought about buying one.


Re: Hobby Charger ?
Written by tandem on 01-17-2011 10:44 AM GMT

BVH, that was my understanding from reading the manual. (PDF)

On page 67 discussing a factory pre-set "LiPo 1s/2s Small Non Balanced" the default charge rate is 350mA with a max possible rate of 2A, no doubt to protect the user from themselves which probably isn't a bad thing for a charger that physically is capable of pumping out 40A. Safety seems to be a theme for FMA which isn't a bad thing.

But for charging a bunch of high capacity 18650's in parallel you'd certainly want higher charge rates than 2A. Hopefully a user defined pre-set can apply a higher rate of charge for "unbalanced" li-ion parallel charging.
:popcorn:

(edit: I've sent the company president a message about this)


Re: Hobby Charger ?
Written by BVH on 01-17-2011 11:13 AM GMT

Thanks,Tandem for your input and as you point out, that Pg 67 paragraph is what is leading me to believe it has the limitation. But maybe as you say, there's a way around it. Looking forward to Clinth's input.


Re: Hobby Charger ?
Written by pae77 on 01-18-2011 02:05 PM GMT

I just wanted to say that I'm very glad I went with the inexpensive Accucell 6 which totally meets my needs and is likely to continue to do so for the foreseeable future. One of the reasons I chose this particular model, aside from the specs, is that it has the right size power input jack for the old laptop power supply I use to power it. So I didn't have to mod anything to get it to work with the power supply I had on hand.

Btw, when I was exploring several layers down in the Accucell program menus, iirc I believe I came across a menu which allows the user to change/set the termination voltage for each battery type charge program, however, the defaults are all fine.

Edit: I just checked and you can only change the voltage "type" to either 3.7, 3.6, or 3.3 nominal voltage for each of the li-ion "types" the charger has programs for. Presumably this also changes the termination voltage as would be appropriate for each of those nominal voltages. But obviously, it's much more limited and less flexible in this regard than I had originally thought.


Re: Hobby Charger ?
Written by radellaf on 01-18-2011 02:08 PM GMT

That's pretty impressive for the price, I'll have to keep an eye on it.

In the meantime, I may end up regretting it if I have a warranty issue, but I just took the side off the BC6 and removed the DC input leads with a soldering iron. I'd only use 12V in for a 7W solar panel, and I don't think this would be the best thing to run off solar. I had the iron out to make up some banana plug leads that were longer and had smaller clips on them, and to try soldering the included banana-to-bare-wire leads directly to the N42SH (hi temp niobium material) magnets I bought earlier. Worked well, and the magnets are still powerful. I'd recommend them to anyone planning to solder to magnets.

I was surprised to find out that the AC feature consists of a laptop-type plastic brick power supply stuffed into the back part of the BC6's case. The 3-prong input is just the back of the brick. Problem with that is that it's not mounted to the side panel, and relies on a little bit of metal on the far end of the brick (output side) to keep it in place. As stiff as the power jack is, I'm betting I'll need to use glue or something before too long. Shame it doesn't use a 2-prong AC input, as it appears the chassis of the charger isn't connected to the ground pin anyway.

Oh, and as for buzzer volume, I put a piece of tape over the buzzer and that cut the volume to maybe half. Still loud, but better for indoors. The original must have been made to hear halfway across a RC airplane flying field.

So nice to be able to do discharge testing on single NiMH cells. The C777 could charge them, but not discharge.

Last bit of odd info - the heatsink for the charger electronics is a piece of metal inside the case, not the case itself. Adequate, I guess, but I'd think if they'd use the case, they could dispense with the fan. <shrug>


Re: Hobby Charger ?
Written by KiwiMark on 01-18-2011 04:45 PM GMT

I just wanted to say that I'm very glad I went with the inexpensive Accucell 6 which totally meets my needs and is likely to continue to do so for the foreseeable future.

I think that this is a great I think that this is a great charger and would meet the needs of most members of this forum. If new chemistries come out later than this charger can't handle then you can buy a new charger, it's not like the Accucell-6 is so expensive that you could never consider replacing it later.

I bought the Accucell-6 and then decided that I really wanted to have a higher discharge rate available so I bought the Accucell-8 (which is also really good value at around $43). Even adding the cost of both chargers together they are not all that expensive, there are plenty of flashlights that cost a lot more.

A suitable power supply can be purchased for $10 and the Accucell-6 for $23, add shipping and it is still cheaper than a Pila cradle charger and 50x as versatile. If someone thinks that a hobby charger might be what they should have then this would be a pretty cheap way to start out. At this price what is there not to like?


Re: Hobby Charger ?
Written by pae77 on 01-18-2011 05:00 PM GMT

Actually, the last time I checked, a suitable power supply for the Accucell 6 was selling on Ebay at aBIN price of $8.50 including shipping. Only way you can beat that is if you have an old laptop brick lying around that has the correct plug and voltage like I did. :)

 

[tandem]

Re: Hobby Charger ?
Written by tandem on 01-18-2011 05:54 PM GMT

I read a few dozen pages of a huge RC group thread on this and came away with "my" understanding that for safety reasons, when using this charger in a manual and non-balancing mode, that it is limited to a two Amp charge rate. Then someone in the know on that thread replied and I didn't quite understand the reply but I think he was trying to tell me otherwise.

And the answer is.... yes! And the answer is.... yes!

I had asked FMA in private and in public:

One of my use cases is charging 2600 and 2900 mAh capacity 18650 lithium ion cylindrical cells, in parallel. Ideally I'd like to be able to select a charging current suitable for at least 0.5C to 1C charge rates, where 1C would be near 18A (6 cells in parallel at ~ 3Ah each).

Is this possible using entirely manual settings or via a user defined preset?

Here's the scoop from Tim Marks who is president of the company and from his many postings on the FMA thread on rcgroups clearly knows his products: Here's the scoop from Tim Marks who is president of the company and from his many postings on the FMA thread on rcgroups clearly knows his products:

Yes, all you would need to do is use one of the balancing presets. The High Power preset would let you charge a single cell up to 40A. The non-balanced preset is for "packs" that will be charged non-balanced. Yes, in this case we limit to 2s non-balanced at 2A max charge rate for safety reasons. There is no safety issue when charging a single cell on a balanced preset.

One way or another, it looks like it is possible. From what I've read it sounds like user defined presets can alter most any parameter so it should be easy enough to create "My Parallel 18650s Pre-set" but even if not I can deal with reusing a predefined one. One way or another, it looks like it is possible. From what I've read it sounds like user defined presets can alter most any parameter so it should be easy enough to create "My Parallel 18650s Pre-set" but even if not I can deal with reusing a predefined one.


Re: Hobby Charger ?
Written by clintb on 01-18-2011 09:52 PM GMT

Good to see you guys got your question(s) answered, and directly from the source.

There's basically a pre-defined set of charging scenarios built into the PL8 which can be altered on the PL8 directly. With the FUIM3 (USB adapter) and CCS, you can change all paramaters and even create your own presets from scratch. I won't lie, it can be a bit daunting to look at CCS, even more so in advanced mode, but a bit of patience and time will have you grasping it in no time at all. Holding the mouse cursor over an option brings up a very good explanation, so you rarely need the help manual.


Re: Hobby Charger ?
Written by radellaf on 01-19-2011 08:49 PM GMT

I use a Mastech 30V 50 Amp PS and love it. I went that large because I use it to run my Locators - 28V, 16 running Amps. If you use a regulated, variable PS, don't forget to install a Schottky Diode in the + output cable to prevent spike/backflow of power to the PS which fried my first Mastech.

Reaching back in the thread a bit, but just wanted to post this after getting my HY1503D Mastech Supply. Quite possibly, they took your advice on the newer model. Have a look at the hefty diodes in series with the negative output binding post. Reaching back in the thread a bit, but just wanted to post this after getting my HY1503D Mastech Supply. Quite possibly, they took your advice on the newer model. Have a look at the hefty diodes in series with the negative output binding post.

http://www.flickr.com/photos/radell...ickr.com/5124/5371331069_3eb49bf71e.jpg[/img]

Unfortunately, this supply is D(efective)oA. 800mA load pulls it down about 0.5V in "CV" mode. Hope they don't ask me to pay return shipping on a 9lb device. Dunno why they don't make these things switching supplies that could weigh maybe 2 pounds, instead.

Turns out I mistakenly bought one of those LiIon cells (batteryjunction's LG Chem 2800mAh) that is supposed to be charged at 4.35V (to 50mA), and since my inflexible Bantam BC6 won't let me change that setting, I'd need this supply to fully charge the cell. Probably wouldn't bother to do it regularly, but it'd be nice to test capacity.

Really waiting for a firmware upgrade...


Re: Hobby Charger ?
Written by Justin Case on 01-20-2011 08:29 AM GMT

If you check the schematicshere for the Mastech HY3005 power supply, you'll see that they use a 3A rectifier (the one labeled V32A in the schematic) to protect the P.S.


Re: Hobby Charger ?
Written by BVH on 01-20-2011 10:42 AM GMT

Thank you - the last 4 posters - for this great info! I appreciate your posts.

Justin, any chance of finding the schematic for the 3050?


Re: Hobby Charger ?
Written by Justin Case on 01-20-2011 11:03 AM GMT

For other Mastech schematics, it looks like you have tocontact these folks.


Re: Hobby Charger ?
Written by radellaf on 01-20-2011 12:55 PM GMT

Well I found out that those diodes were a (bone headed) hack, as they cause the voltage to drop unde load (CV should be CV, hence the word "regulated"). I heard back and they were thrown in to "prevent damage from misuse".

Fine, but either put them backwards and shunt, or move the bloody voltage monitoring feedback to the regulator to the _load_ side of the diodes (and make sure it can handle reverse voltage spikes). If the circuit can't handle -0.7V spikes then there's a more fundamental design issue.

You sure do get what you pay for with test equipment. But, at least I can fix this without payin return shipping.


Re: Hobby Charger ?
Written by BVH on 01-20-2011 01:08 PM GMT

With my Schottky in the + output, I lose .5V under no-load and loaded at any Voltage/current. I just know to subtract .5 from the Voltage display. I'd love to by a surplus Lambda 40V -60A supply but they still want $1,300+ for them.

Re: Hobby Charger ?
Written by radellaf on 01-20-2011 01:40 PM GMT

Might be fine for some apps but testing MCU based lights I don't want 4.2V under load to jump to 4.7V (for example) when the circuit switches to standby. Or worse, 1.5V to go up to 2.0V.

The specs say 3mV load stability and I need no more than 50mV to get useful test results on some of my applications. Series protection is just no good.

That schematic is weird, tho it explains why the hack diodes are in series with the - terminal. They're using ground for the positive and using a negative supply. I don't know why...

Also, looks like the LM324 op amp may be to blame for the delicate input. There are much more... robust versions of that developed in the last, oh, 30 years?

I can't afford a "real" supply ($500+) but if this were $100 instead of $50 I would still have bought it, and probably liked it better. Good price for what components are there, to be sure, but they cut too many corners.

---edit---

Just heard back from Mastech and apparently it's not kV of backvoltage that is the problem, but anything driving the input at a higher voltage than the supply is set for. i.e., set it to 3V, attach a LiIon cell, and (presumably) POOF.

That is _bad_ design. I'll have to see about maybe sending it back. As is, it doesn't come close to meeting advertised specs, and without the diode it, apparently, can't power: "DC motors, batteries, fan, electrochemical systems, capacitors, inductors, thermal electrical coolers, etc."

Might as well call it an incandescent light bulb driver instead of a power supply. Yikes. It's going back to them.

Just found this new one from BK that might be just what the Dr. ordered: http://www.testequipmentdepot.com/bk...n/pdf/1550.pdf

$140, 5 lbs, Switching DC Power Supply 1-36V, 0-3A. The equivalent DC version is $240, and larger/heavier than the Mastech.


Re: Hobby Charger ?
Written by Justin Case on 01-21-2011 01:29 PM GMT

Well the two paralleled rectifiers make that series diode protection approach even more of a hack. There is probably little guarantee that those two rectifiers are closely matched.

It also looks like your series diodes protect only against current backfeed. There is still the issue of reverse polarity, which IMO could be a higher probability failure mode when using a bench supply to charge an individual cell or a pack.

A bridge rectifier and a fuse will easily and simply address both issues. See here under "Basic Operation", for an example bridge hookup. A Fairchild GBPC35 series bridge should work fine. Put a fuse with appropriate amp rating in series with the upper right, red output lead in the example bridge hookup diagram.

With this circuit, using a bench supply to charge bare cells should be about as safe as it gets. You should be protected against current backfeed and reverse battery polarity connection (should just blow the series fuse in the circuit). Also, if you connect the circuit with reverse polarity to the bench supply, that should not matter.

A remaining issue (besides the fact that there is no automatic charge termination) is the voltage drop from the diodes which messes up the target charging voltage that you set on the bench supply. From the Fairchild datasheet, Vf can vary from about 0.7V to 1.0V for a forward current of 1A to 10A. Thus, you might not be able even to assume a constant Vf drop.

A workaround for that is to get an inline wattmeter, such this or this or this. From the wattmeter voltage readout, set the bench supply so that the wattmeter reads the desired voltage.


Re: Hobby Charger ?
Written by radellaf on 01-21-2011 03:57 PM GMT

Bridge would be a good way to blow a fuse on Vload > Vsupply. Would prevent true CC/CV charging since the diode drop would probably go down a few 10s of mV as the current went from say 300mA down to 50mA (e.g., topping off one of those 4.35V 2.8Ah LG Chem cells). You'd have to find out what, at 50mA, gave you 4.33-4.35 at the cell, which would probably be a lower setting than the one that gave you that voltage at 300mA.

The diodes are a hack and they as much as admitted it. Called it a "stop-gap solution". Stop gap my foot, they shouldn't be selling these things. Add to that, they're "soon" coming out with an improved version of the HY1503 (and I presume others in that family) that are overvoltage protected on the input. You might still want a reverse diode if you're driving inductive loads. The screwy part about their current design isn't that the input objects to being driven below 0V, but that it has a problem being driven any higher than the set voltage. Not sure how they designed a regulator that doesn't just say "OK, Vout is too high, I'll shut off my pass transistors now".

So, I sent my unit back (they paid return shipping, I'm still out $20 s/h though), and I'm trying to get them to do an even exchange with an improved unit whenever they're released.

I'm also looking at the $50-$250 alternatives. The BK supplies are more robust (they were a bit amused about Mastech's problem and "fix"), and the 1550 is both small and quiet (NO FAN), but voltage adjusts in 0.1V steps, not so good for LiIon. Also, CC limit can take a moment to kick in (i.e. could blow your LED). The BK1621 is what the HY1803 wants to be, but is double the size of the HY1503.

Then there's this odd duck of a USB programmable supply, the $200 Quako HY3005DP, which is as small as the 1550 and much more configurable. Also has a nice obvious LED indicator for when its over-voltage protection is active. Looks ideal, if I could trust its reliability vs. the BK Precision supplies ($350 and much larger for their 1696 programmable, which is RS232 only).

I'm looking into whether either programmable supply can be set to shut off when the charging current drops below a threshold. Even if it required a full-time attached PC. The BK will for sure do that if you have LabView, but not sure about the included SW. It would also let you graph volts/amps just like you can from the Bantam-type hobby chargers.

--on topic--

And, to boot, I've bugged Bantam about adding a manual or preset mode for the 4.3/4.35V cells. They did reply to my first email, arguing such cells didn't exist. I haven't heard back since sending them links to both Samsung and LG datasheets for the ones that do.
--back off--

FWIW, while I had it, and shorted the diode, I was able to verify that the Zebralight SC60 does have effective 2.75V cutoff, even at low brightness settings. The P-Rocket shuts off to a low-drain blink mode at 2.5-ish (and also is VERY badly regulated. supposed to be 2.5A max but it went up to 2.8A as I upped the voltage a few 100mV). The first 10-20 min on the P-Rocket would really benefit from the 4.35V 18650, though. I think I got one with a high Vf emitter. The Quark RGB, well, you have to check. At 2.75-3-ish, level 3 is same brightness as turbo. You can check any time, but if you left it to run at lvl moon-2-or-3, you'd spend a lot of time under 2.75V.


Re: Hobby Charger ?
Written by Justin Case on 01-21-2011 08:48 PM GMT

Bridge would be a good way to blow a fuse on Vload > Vsupply. Would prevent true CC/CV charging since the diode drop would probably go down a few 10s of mV as the current went from say 300mA down to 50mA (e.g., topping off one of those 4.35V 2.8Ah LG Chem cells). You'd have to find out what, at 50mA, gave you 4.33-4.35 at the cell, which would probably be a lower setting than the one that gave you that voltage at 300mA.

Whoops. I mistakenly described the desired bridge circuit. V(ps)- and V(load)- both connect to the node at 3 o'clock on the bridge shown in the wikipedia link. V(load)- does not connect to the node at 6 o'clock. Whoops. I mistakenly described the desired bridge circuit. V(ps)- and V(load)- both connect to the node at 3 o'clock on the bridge shown in the wikipedia link. V(load)- does not connect to the node at 6 o'clock.

If Vload > Vps, for example when the ps shuts off unexpectedly (power failure, fat finger, or whatever), the bridge prevents any backfeed of current. The fuse should not blow because there is no current flow anywhere.

Other than that, Vload shouldn't be greater than Vps anyway. We are talking about a battery charging application, and specifically in the case of CC/CV, Li-ion charging. Thus, you would set your ps such that Vps is some multiple of 4.20V. The cells being charged will have a Vload less than Vps. Vload will begin to rise at the set current until the set voltage is reached. Then the supply switches over to constant voltage mode and the current starts to decrease while the float voltage holds at the set voltage (assuming adjustable current limits).

Yes, there is the issue of Vf drop from the diodes, as I mentioned. And that drop is not a constant, but varies somewhat with current. Hence, my suggestion to use a Watt Meter or similar device. This would affect the CV phase of the charging, not the CC phase. Depending on the sensitivity of the diode Vf with charge current magnitude, you might have to periodically tweak the power supply voltage to keep the float voltage at 4.20V. It is true that the Fairchild GBPC bridge rectifier datasheet shows Vf changing from about 0.7V to 1.0V for a forward current range of 1A to 10A. But datasheet specs and real world specs sometimes differ. You really have to check to see how your bridge's Vf varies over your forward current range of interest.

Charging cells with a bench supply isn't like dealing with the simplicity of charging with a Pila or even with a hobby charger. There is no automatic charge termination, no temperature cutoff, no max capacity cutoff, no timer cutoff, etc etc. You are the primary, secondary, and tertiary safety circuits.


Re: Hobby Charger ?
Written by radellaf on 01-23-2011 12:09 PM GMT

Granted the battery voltage _should_ be lower than the power supply output, but I'm sure not keeping a power supply that is going to blow out permanently if I ever twist the knob to 3V while 4.2V charging. Like I said, with all their restrictions on what it can't safely power, all it leaves is resistors and light bulbs.

Re: Hobby Charger ?
Written by Justin Case on 01-23-2011 01:08 PM GMT

Granted the battery voltage _should_ be lower than the power supply output, but I'm sure not keeping a power supply that is going to blow out permanently if I ever twist the knob to 3V while 4.2V charging. Like I said, with all their restrictions on what it can't safely power, all it leaves is resistors and light bulbs.

Well, #1 that's what the bridge is for. #2, obviously a bench supply is not the same as a dedicated Well, #1 that's what the bridge is for. #2, obviously a bench supply is not the same as a dedicated charger in terms of being dummy-proof. If you are prone to be a knob/button-twiddler, then a bench supply is the wrong device to use to as a Li-ion charger, regardless of the design/quality of the bench supply. Get a Pila charger. Even a hobby charger would be the wrong choice IMO for a knob/button-twiddler.


Re: Hobby Charger ?
Written by radellaf on 01-25-2011 01:02 PM GMT

There's a difference between something requiring knowledge to work, and something being built so badly that it is fragile under normal operating conditions. Tell me you've never had your meter on amps when you wanted volts, for instance. A power supply should be really tough.

The bridge is too much trouble, whole idea of a lab power supply is to _not_ have to keep changing the voltage as the current changes.

So, until the newer version comes out, the cheapest supply that will work is the 18V 5A BK 1621A for about $200. A lot but about half what I expected. If it wasn't so huge I might have already bought one. As is I'll keep an eye out for something smaller and cheaper.


Re: Hobby Charger ?
Written by Justin Case on 01-25-2011 09:02 PM GMT

There's a difference between something requiring knowledge to work, and something being built so badly that it is fragile under normal operating conditions. Tell me you've never had your meter on amps when you wanted volts, for instance. A power supply should be really tough.

The bridge is too much trouble, whole idea of a lab power supply is to _not_ have to keep changing the voltage as the current changes.

So, until the newer version comes out, the cheapest supply that will work is the 18V 5A BK 1621A for about $200. A lot but about half what I expected. If it wasn't so huge I might have already bought one. As is I'll keep an eye out for something smaller and cheaper.

Plenty of folks on the RC groups are using bridges and other rectifier networks when re-charging their Li-ion packs using Mastech bench supplies. So I fail to see why a bridge is "too much trouble". The whole idea of using a bench supply as a Plenty of folks on the RC groups are using bridges and other rectifier networks when re-charging their Li-ion packs using Mastech bench supplies. So I fail to see why a bridge is "too much trouble". The whole idea of using a bench supply as a charger is already somewhat of a hassle. The bridge seems very incremental. However, I personally don't see using a bench supply as a general-purpose charging method anyway. The RC folks seem to use big bench supplies to re-charge their A123 packs very rapidly by hitting their big packs with max current. I don't have that requirement. Using a bench supply to power my hobby charger seems a lot more useful.

Putting a DMM on amps instead of volts is hardly the same thing as screwing up the settings or charging procedure for a bench supply when charging Li-ions. With a DMM, you'll probably just blow a fuse or at worst, fry your meter. With a bench supply screwup, you'll be lucky if all that happens is that your blow a rectifier or fuse in your bench supply, or even have nothing at all happen to your supply. The worst case is that you might have a serious vent with flame incident. Internal circuitry to protect the supply itself is all well and good. But don't forget about thermal runaway of the cells/entire pack if you screw up.

If you can't provide the necessary attention to detail when using a bench supply as a charger, then IMO that is simply the wrong tool to use, regardless of bench supply brand/design.

In post #83, you gave the example of "...if I ever twist the knob to 3V while 4.2V charging...". Frankly, if you are vulnerable to such an operating error, you should not use any type of bench supply to charge any kind of Li-ion cell -- safe chemistry, protected, or whatever. Why would you even touch the voltage settings while already charging at the correct float voltage of 4.2V? That is a fundamental error.


Re: Hobby Charger ?
Written by BVH on 01-25-2011 09:13 PM GMT

Looks like a lot of the RC people are using Iota battery chargers that also double as a fairly stout and stable PS. I've had the DS55 ever since I needed some heavy duty charging for my 24V, 220 Amp AGM battery setup for my VSS-1. I just brought it out of storage to power my newPL8 charger. Don't know why I didn't think of this before. Looks like Iota 55's are going for about $180 give or take. Not too bad for 13.5V, 55 Amps.


Re: Hobby Charger ?
Written by radellaf on 01-26-2011 03:09 AM GMT

I know how to use the equipment, and I know when what I just bought is poor quality and doesn't match what its spec sheet says. I'm glad Mastech is (eventually) going to redesign their supplies to fix their problem. In the meantime, I would like a smallish adjustable CC/CV supply that actually works, if anyone knows of one I haven't mentioned, since Bantam doesn't seem interested in supporting 4.35V cells.

Re: Hobby Charger ?
Written by tandem on 02-01-2011 09:19 AM GMT

I recently became an owner of the FMA CellPro PowerLab 8 (that's a mouthful) which is a 1300Wcharger aimed at the RC market and sadly about five times the cost of a decent 50W hobby charger. On a cost per watt basis it's pretty decent though.

I notice that the max charge voltage in the latest (and perhaps the prior) version of the charge control software is 4.3V which might be close enough for someone interested in the Samsung 4.35V cells. I've already put a plug in for these cells on the wish list forum for the charger maker over on RC Groups.

A few of us here at CPF have the PL8 -- maybe one of us will consent to doing a review or we pile observations into a joint review thread.


Re: Hobby Charger ?
Written by HKJ on 02-01-2011 09:27 AM GMT

I notice that the max charge voltage in the latest (and perhaps the prior) version of the charge control software is 4.3V which might be close enough for someone interested in the Samsung 4.35V cells. I've already put a plug in for these cells on the wish list forum for the charger maker over on RC Groups.

You can do the same on the iCharger and probably a lot of other chargers to. The upper limit for LiIo is 4.2 and for LiPo is 4.3, i.e. it is possible to redefine the charge voltages to 4.2/4.3 instead of 4.1/4.2. for LiIo and LiPo You can do the same on the iCharger and probably a lot of other chargers to. The upper limit for LiIo is 4.2 and for LiPo is 4.3, i.e. it is possible to redefine the charge voltages to 4.2/4.3 instead of 4.1/4.2. for LiIo and LiPo



Re: Hobby Charger?
Written by BVH on 02-01-2011 09:35 AM GMT

A few of us here at CPF have the PL8 -- maybe one of us will consent to doing a review or we pile observations into a joint review thread.

I just picked one up but I don't own any balanced packs - yet so am not taking advantage of the power it is capable of. I have not seen any method around the 2 Amp charging limit on unbalanced packs. I just picked one up but I don't own any balanced packs - yet so am not taking advantage of the power it is capable of. I have not seen any method around the 2 Amp charging limit on unbalanced packs.


Re: Hobby Charger?
Written by tandem on 02-01-2011 10:29 AM GMT

BVH what are your "packs"? A single cell or multiple cells in parallel? In series?

(edit: I saw your note in the FMA Direct forum on RC Groups. Now I understand. Looking forward to seeing the answer.)

Haven't got to parallel charging cells yet but will soon.

I have been able to observe a > 2A charging rate on a single cell. For the preset I chose 2.5A but rates up to 10A were available to me.

I seem to recall there is a setting which can unlock higher rates but under what conditions I'm not certain, yet. There's a lot to explore in this unit. I'm running the latest firmware and charge control software.


Re: Hobby Charger?
Written by KiwiMark on 02-01-2011 06:14 PM GMT

You can do the same on the iCharger and probably a lot of other chargers to. The upper limit for LiIo is 4.2 and for LiPo is 4.3, i.e. it is possible to redefine the charge voltages to 4.2/4.3 instead of 4.1/4.2. for LiIo and LiPo

That would be one of the reasons that I am looking at buying an iCharger. That would be one of the reasons that I am looking at buying an iCharger.


Re: Hobby Charger?
Written by BVH on 02-01-2011 06:22 PM GMT

BVH what are your "packs"? A single cell or multiple cells in parallel? In series?

(edit: I saw your note in the FMA Direct forum on RC Groups. Now I understand. Looking forward to seeing the answer.)

Was just going to explain but see that you saw my post on RC. I hope they can be charged. To me, it makes no sense for such a high power and feature rich charger to not be able to handle this task. Was just going to explain but see that you saw my post on RC. I hope they can be charged. To me, it makes no sense for such a high power and feature rich charger to not be able to handle this task.


Re: Hobby Charger?
Written by tandem on 02-01-2011 06:47 PM GMT

It seems the 1SnP configuration it can handle which is my use case, in addition to some bog standard balance charging of RC packs (also in parallel now). Hopefully this use case of yours isn't the exception.

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