Re: Best Do-Everything Charger
Written by
SilverFox on 02-19-2011 03:32 PM GMT
Schulze built their reputation on charging nickle based battery packs. Their Auto algorithm does wonders on packing more into the pack, and also it seems to hold the cells in balance longer.
I have several pieces of test equipment that run on nickel based battery packs, and I have been totally impressed with the performance of the Schulze charger to keep them in very good shape. I have seen a 12 - 15% increase in run times over the chargers that came with the equipment.
Now that the emphasis seems to have moved to Li-Ion chemistries, I am not sure the Schulze holds any "advanced" algorithms in that area, but I haven't kept up on their advancements.
The reasons I purchased my Schulze,
High quality.
Ability to charge lead acid chemistry, and it does a very good job at this.
Ability to charge Li-Ion chemistry. It does a pretty good job at this, but is subject to lead wire and connection resistance.
Ability to charge two different packs at the same time. While channel 2 charging is limited on my unit, I have used it often and find it very useful.
Ability to monitor the charging progress on my computer.
And finally, and most importantly, the ability to charge large numbers of nickle based cells and pack more into them than other chargers can. I also find the long term forming function very valuable in recovering abused battery packs, and have used it to break up minor sulphation in lead acid batteries.
That's my $0.02 on the Schulze.
Tom
Re: Best Do-Everything Charger
Written by
CKOD on 02-20-2011 12:56 AM GMT
...
You'll also need a power supply for most chargers being discussed in the thread; if you really want or need a PL8 and want 1344 watts out you'll need a significant power supply - 24V, high current, and that will run you some coin. I'm driving mine with a 10A bench supply so my max output power is far from 1344 watts but is ample for what I'm doing at present, but won't be sufficient for driving the charger to handle the power required for larger numbers of larger capacity lipo packs in parallel. I do have a 12V server power supply sitting idle here waiting for me to get round to converting it to drive the charger.
PS: Charging a few 18650 cells at 0.3C or 0.7C or 1.0C doesn't require a lot of input or output power. Singly we are talking just a few watts and in parallel you can add a few watts up and get to not many 10s of watts input required. For a lot of what I do my 130 watt bench supply is more than sufficient and in fact I really only need really high output when at the flying field if I were charging many packs in parallel at high rates which is not the norm for me at all, least not at this point.
Another thing to note, if you want the full 1kw+ discharges with the Another thing to note, if you want the full 1kw+ discharges with the PL8, then you need a battery for it to dump the load into. So if you want to do heavy battery cycling, then a nice SLA or 2 may be of interest. Plus you could use a cheaper lead acid charger and let the battery handle the 50+A current the PL8 needs for high power pack charging. You could even just use a cheapie power supply and use PL8 to charge your SLA bank after its done charging your other cells from the battery. :duh2:
Or you could use an electronic load to sink the current from the PL8
http://www.bkprecision.com/products/...onic-load.html :duh2:
Re: Best Do-Everything Charger
Written by
45/70 on 02-20-2011 08:52 PM GMT
CKOD said:
Good point, In fact isnt the preferred termination method for newer nickel cells delta temp/time instead of dv/dt? Since the voltage sag which can be missed is caused by an increase in the temp? Seriesed cells for charging which weren't discharged seems like it would always be sub-optimal. and for good dtemp/dtime you'd want a temp sensor embedded in the pack rather then just a temp sensor on the other side of a plastic cradle.
Your points highlight the shortcomings of series charging nickel based cells. Ideally, a Your points highlight the shortcomings of series charging nickel based cells. Ideally, a charger should always have more than one way of determining charge termination for
each cell. Unfortunately, there isn't really any way to do this when charging nickel based cells in series, or at least any way that is practical.
If a balancing setup could be implemented, similar to how Li-Ion cells are charged in series, it maybe could work, but would be much more complex, having to monitor each individual cell for both -dV, and temperature, for example. It could probably be done, but I can only imagine what the cost of such a charger would be.
Dave
Re: Best Do-Everything Charger
Written by
hazna on 02-21-2011 02:47 AM GMT
Are there any reasonably pricehobby chargers that can detect the -delta V? I recently bought the accucell 6, but am dissappointed it can't detect -delta V and misses termination. I now set termination when expected capacity is reached... however I feel I need to fully discharge my battery if I am going to do this.
Re: Best Do-Everything Charger
Written by
HKJ on 02-21-2011 03:32 AM GMT
hazna said:
Are there any reasonably price hobby chargers that can detect the -delta V? I recently bought the accucell 6, but am dissappointed it can't detect -delta V and misses termination. I now set termination when expected capacity is reached... however I feel I need to fully discharge my battery if I am going to do this.
Have you tried adjusting the DV threshold? Have you tried adjusting the DV threshold?
Re: Best Do-Everything Charger
Written by
hazna on 02-21-2011 04:03 AM GMT
yeah i've tried adjusting it down to 5mv, which seems to be it's lowest setting. No luck, though
Re: Best Do-Everything Charger
Written by
zehnmm on 02-21-2011 07:37 AM GMT
+1 on the Schulze. I lucked out and found mine from Ebay for a song. Same thing for my Mastech power supply.
Re: Best Do-Everything Charger
Written by
45/70 on 02-21-2011 09:20 AM GMT
hazna said:
yeah i've tried adjusting it down to 5mv, which seems to be it's lowest setting. No luck, though
I've found that when charging 2-4 cells, a 5mV -dV works most of the time. When charging 6, 8, 10, 12, or 13 cells though, any more I charge at a 0.5C rate. When I notice any area of the pack starting to get warm, I stop the charge, reduce the charging current to 0.1C, then resume charging at the lower rate. I've found that when charging 2-4 cells, a 5mV -dV works most of the time. When charging 6, 8, 10, 12, or 13 cells though, any more I charge at a 0.5C rate. When I notice any area of the pack starting to get warm, I stop the charge, reduce the charging current to 0.1C, then resume charging at the lower rate.
Sometimes, with newer cells, the charge will terminate by -dV without any cells getting hot. Particularly with older packs however, I simply charge the pack another couple hours at the 0.1C rate then terminate the charge manually. Otherwise, some cells will get really hot, with some cells obviously missing termination even at 5mV -dV.
Dave
Re: Best Do-Everything Charger
Written by
Battery Guy on Unknown
What about chargers that don't require a DC power supply? I would like to buy acharger that is capable of balance charging a 5 or 6 cell series string of lithium-ion cells, and up to about 24 V for NiMH packs, but I want to be able to plug directly into 110 AC. I would also like the ability to select the cut-off voltage for lithium-ion charging. Anything out there that can do this?
Cheers,
BG
Re: Best Do-Everything Charger
Written by
HKJ on Unknown
Battery Guy said:
What about chargers that don't require a DC power supply? I would like to buy a charger that is capable of balance charging a 5 or 6 cell series string of lithium-ion cells, and up to about 24 V for NiMH packs, but I want to be able to plug directly into 110 AC. I would also like the ability to select the cut-off voltage for lithium-ion charging. Anything out there that can do this?
Cheers,
BG
A hobby charger with buildin power supply. There are some, you just have to look around.
Re: Best Do-Everything Charger
Written by
tandem on Unknown
Hyperion and Thunder Power both make AC/DC powered chargers and both are probably better than the usual Bantam clones you'll find out there. Bantam also has a couple AC/DC chargers in their line up.
Whether or not it is due to the cloning of the Bantam line and thinning out of their market share, Hyperion and Thunder Power seem to be somewhat more popular in the RC crowd at present. Both of the latter also make highly regarded lipo battery packs which may also in part be why. Thunder Power packs tend to be regarded as the king of the hill right now, and command prices to match the reputation.
If you narrow your choices down and do a search on rcgroups.com no doubt you'll find some validation.
Re: Best Do-Everything Charger
Written by
45/70 on Unknown
Battery Guy said:
What about chargers that don't require a DC power supply?
Back when I was reading through the R/C forums researching Back when I was reading through the R/C forums researching hobby chargers, there were two things that were recommended to avoid. Chargers with fans, and chargers with a built in power supply. It seems these are the first two items to fail in the more inexpensive chargers, <$100. Having some insight as to the quality of charger you're most likely looking at BG, this probably isn't a problem for you. The higher end chargers likely have better components and these two items probably are not much of a problem.
As for the ability to select Li-Ion CV stage voltage, most chargers are pretty much limited to 3.6, 4.1, and 4.2 volts (LiFe, LiIo, and LiPo respectively). Some chargers have an adjustment available for this voltage, but as I understand it, it is only +/- a few hundredths of a Volt.
Most hobby chargers also have a "fast charge" mode, which I usually use, which the only difference is that charge is terminated at C/5 instead of C/10. This effectively terminates the charge in between 4.10 and 4.20 Volts with LiCo (or LiPo) cells when the CV voltage is set to 4.20 Volts, or "LiPo" (and I suppose 4.00 and 4.10 Volts when set to 4.10 Volts, or "LiIo").
Also, most hobby chargers offer a "storage charge" mode which charges (or discharges) cells to 3.30, 3.70, or 3.80 Volts (LiFe, LiIo, LiPo). So anyway, there is
some flexibility with these chargers, but I imagine you'd have to go to a higher end charger to gain much more range as far as setting a custom CV voltage.
Dave
Re: Best Do-Everything Charger
Written by
tandem on Unknown
Dave,
Poor quality clones probably have more to do with one aspect of the advice you've seen given on RCGroups - fans. Only chargers limited to fairly low rate charging would be shipped without fans these days. The Bantam clone units like the Accucell all appear to have fan noise issues but many add a drop or two of lube and the problem seems to go away. Fans are fairly cheap and easy to replace at any rate. I've no solid sense of how Bantam units themselves are held by the community but I have noted lately in discussion on RCGroups both clone and original units implicated in balance charging failures (in my mind) with one cell in a pack reaching 4.5 - 4.8V. No matter what the cause this seems like a bug and a surprising one at that.
As for AC/DC chargers as long as properly built they have a place, but likely are not endorsed as often as they tend to be limited in output power and therefore wouldn't be a good fit for someone needing to charge numbers of larger capacity packs at high rates or especially at high rates in parallel which is definitely the trend of late. It is easy to run into max power output limits on entry level 50W chargers even for those flying nothing but small foam craft with modest power requirements - many of these are powered by 2S packs with < 1000 mAh capacity. Sure you can charge a handful of these in parallel at ~ 8W output required per pack with even a relatively modest charger... just not at high C rates. AC/DC chargers usually offer more output on DC input though which may help some. Also... when charging at home usually one is in less of a hurry than when at the field.
It isn't clear to me that the Hyperion - ~ $120 - $280 depending on model - has the flexibility for max voltage threshold BG seeks but I think it does; I find their manuals poor. It could be / probably is the
parameter "TCS Capacity" (measured in percent) is how you manage this with their charger; I rather prefer to set it by nV per cell. The
ThunderPower 610C - ~ $100 - also uses a percentage figure as does the Korean made
Bantam BC6DX-II - ~ $150 up - (and higher max output power BC8DP). As far as I know all three feature user-driven firmware updates.
Re: Best Do-Everything Charger
Written by
Battery Guy on Unknown
Thanks for the info gents. It is really very helpful.
Currently I am considering the Hyperion HP-EOS0720i NET3 AC/DC. Since I am not into RC hobby racing, I don't think that I need to have two independent charging channels, so the DUO seems over kill.
Anyone see a down side to this charger?
Thanks for your advise.
Cheers,
BG
Re: Best Do-Everything Charger
Written by
45/70 on Unknown
Dave,
Poor quality clones probably have more to do with one aspect of the advice you've seen given on RCGroups - fans. Only chargers limited to fairly low rate charging would be shipped without fans these days.
Ah, yes, you're right. I was thinking about <50 Watt chargers like I have (a cheap clone). Of course, BG is looking at something quite a bit larger and yes, it would no doubt require a fan. Ah, yes, you're right. I was thinking about <50 Watt chargers like I have (a cheap clone). Of course, BG is looking at something quite a bit larger and yes, it would no doubt require a fan.
As for the <50 Watt chargers, there really isn't any need for a fan, provided the heat sinking is adequate, IMO. These are transistors being cooled, not processors. They are designed to run hot,
very hot. With more than 50 Watts or so though a fan would probably be needed, particularly in the interest of keeping the charger relatively small in size. Passive heat sinking can only go so far.
IMO, regardless of the size or quality of the charger, you're way ahead to keep the charger and the PS separate, for heat issues, if nothing else. That may just be my way of thinking though. I always buy separate components for my high end audio. It's the amp that always fails first, so why not keep the major heat source away from everything else, for example.
Dave
Re: Best Do-Everything Charger
Written by
Battery Guy on Unknown
45/70 said:
I always buy separate components for my high end audio. It's the amp that always fails first, so why not keep the major heat source away from everything else, for example.
Dave
Oh how I truly the miss the days of matching audio components. Remember how important it was to match your stylus to your tonearm to your turntable? And playing a beloved song was a ritual involving cleaning of the stylus and the vinyl? The music seemed to sound better back then, even if the technology was primitive. Perhaps I am turning into an old fart. Oh how I truly the miss the days of matching audio components. Remember how important it was to match your stylus to your tonearm to your turntable? And playing a beloved song was a ritual involving cleaning of the stylus and the vinyl? The music seemed to sound better back then, even if the technology was primitive. Perhaps I am turning into an old fart.
Well Dave, I think that you and I have a lot in common with respect to audio, because I still have separate components. But when it comes to charging my flashlight battery packs at home, I am inclined to go for the "receiver" instead of the "amp/pre-amp/tuner" option. I have access to high end battery test gear as part of my normal job, so I really just need something that is reliable and safe for home charging of battery packs.
Any negative issues with the Hyperion that I should know about?
Cheers!
BG
Re: Best Do-Everything Charger
Written by
45/70 on Unknown
Battery Guy said:
Oh how I truly the miss the days of matching audio components. Remember how important it was to match your stylus to your tonearm to your turntable? And playing a beloved song was a ritual involving cleaning of the stylus and the vinyl? The music seemed to sound better back then, even if the technology was primitive. Perhaps I am turning into an old fart.
Music is an analog experience, at least if you play "real" instruments it is. And yes, that includes electric guitars. So the music Music is an analog experience, at least if you play "real" instruments it is. And yes, that includes electric guitars. So the music
did sound better.
Also, you forgot to mention the disk preener!
Actually, I'm presently looking into a turntable. Also,
tube amplifiers. The biggest problem I had when CD's came out was that cymbals sounded more like garbage can lids than cymbals!
Dave
Re: Best Do-Everything Charger
Written by
KiwiMark on Unknown
45/70 said:
As for the ability to select Li-Ion CV stage voltage, most chargers are pretty much limited to 3.6, 4.1, and 4.2 volts (LiFe, LiIo, and LiPo respectively). Some chargers have an adjustment available for this voltage, but as I understand it, it is only +/- a few hundredths of a Volt.
The iChargers have the ability to set the CV stage voltage, by more than a few hundredths. The iChargers have the ability to set the CV stage voltage, by more than a few hundredths.
LiFE - 3.40V-3.90V
LiIo - 3.90V-4.20V
LiPo - 4.00V-4.30V
For this feature and a few others that aren't on the cheaper chargers I have just ordered an iCharger 106B+ for under $100 shipped. I think that if you include the price in the equation this could be the best charger available (depending on what features you want/need) and I'd rather buy 2 of these than one of the dual channel Schulze chargers (because the Schulze chargers are just too expensive for me). I also wanted to be able to charge at 0.05A which the iCharger can do, but the cheaper chargers usually only go down to 0.10A which is a bit high for some tiny batteries, 0.05A to 10.0A seems like a pretty flexible range of charging current to me. The iCharger comes with a temperature probe which is nice for another cut-off option for better safety, you then have time, temperature & capacity cut-off options available which you can disable or enable and set parameters for.
For the best charger I'd recommend:
On a tight budget I'd recommend the Turnigy Accucell-6 at $23 + shipping. It's a really good charger with lots of great features for a great price.
On a higher budget I'd recommend the iCharger 106B+ for $80 + shipping. It's a better charger with better features, obviously you have to pay more for it.
On an unlimited budget the Schulze chargers look to be the best, but of course you pay so much more for them.
My own charger configuration:
iCharger 106B+ (on the way)
Turnigy Accucell 8 (bought back when it came with the thermal probe)
2 x LaCrosse BC-900 chargers (I've had them for a few years and have never had a problem, each can charge 4 x AA/AAA NiCd/NiMH with 4 independent channels and settable charge current)
2 x WF-139 (each have 2 independent channels, but I don't use these much - my hobby chargers are better)
Yeah, I can get a lot of batteries charged in a fairly short time.
I have a computer PSU that provides power to my 2 hobby chargers, they can also be powered by any car battery if needed. (they can also charge a car battery with the Pb setting)
