Pila IBC Charger Compendium

[kurni]

Should be ok, it has "raised" plus terminals, don't need magnets.

Thanks cernobila, I just bought from flashlightz.

You mean something like this?

That gives me an idea; what if I have 2x14670 holder in paralel for each bay, so that I can charge 4x14670 at the same time? I understand the voltage-difference risk, but these 4x14670 will be used at the same time in a FM holder so significant out-of-balance would be unlikely. Would it be safe?

Thanks in advance,
Kurni

 

[cernobila]

Thanks cernobila, I just bought from flashlightz.



That gives me an idea; what if I have 2x14670 holder in paralel for each bay, so that I can charge 4x14670 at the same time? I understand the voltage-difference risk, but these 4x14670 will be used at the same time in a FM holder so significant out-of-balance would be unlikely. Would it be safe?

Thanks in advance,
Kurni

No good, only charges two cells at a time.

 

[VanIsleDSM]

Not a bad charger.

Still missing some key safety features though.

It should be 5 stage, after qualification there should be a trickle charge to bring deeply depleted cells to ~2.9V before hitting them with 600mA. Charging a smaller cell @ 600mA that was only @ 1V would be quite hazardous.. and create a lot of heat in a linear charger.

Secondly there should be continuous temp monitoring for each cell with automatic shutdown.

And finally, the charge current should be adjustable to safely charge smaller cells.

 

[SilverFox]

Hello VanIsleDSM,

While it does have some drawbacks, the Pila IBC charger is about the best "off the shelf" cheap charger available.

It is actually designed to charge Pila cells, which are protected against over discharge. If one were to only used protected cells with it, there would be no concern with over discharged cells.

I think a Li-Ion charger should reject a cell that is under 2.75 volts and not bother with trying to revive it at all. However, I seem to be in the minority with that opinion. Most cells can be revived from being discharged to a lower voltage, so perhaps my opinion is conservative.

You do bring up a valid point. I addressed this in a earlier post, but it should be repeated. The smallest capacity cell that should be charged on the Pila charger is one that has at least 600 mAh of capacity. Charging a smaller cell, especially if the cell has been over discharged, exceeds the recommended 1C maximum charging rate recommended by the cell manufacturers.

The idea of heat monitoring while charging Li-Ion cells is interesting. Unfortunately, heat is not a usual byproduct of charging this chemistry. When thermal runaway begins, it usually progresses very rapidly and I am not sure you would pick it up in time to prevent it.

I don't think it is a bad idea to incorporate heat monitoring, I just am not sure how beneficial it actually is.

Overall, with its universal voltage compatibility, and a step down adapter to enable powering it from 12 volts DC, it is very attractive. I agree that it would be nice if it had multiple charge rates, but it does a pretty good job just the way it is.

Tom

 

[VanIsleDSM]

The heat monitoring validity is an interesting issue.

I can't say how useful it is, only that almost every single med-high quality Li-Ion charging IC has an option for temperature monitoring. I assume, because of that, that it is useful, but I would love to see some data or an experiment.

If you look at your cell phone Li-Ion battery there is a connection for temp monitoring, I also see one on my digital camera battery.

I know the charging chemistry barely heats as charged, but what about when overcharging begins? say if a 3.0 Li-Ion was accidentally being charged.. would it start to heat during overcharge? I imagine so.. and if you keep charging it.. well.. I imagine there would be some nastiness, however if the temp cut-off kicked in at the first sign of too much heat, you could save an ugly situation.

Is there a demonstration of what happens to a 3.0V cell in a 3.7V charger? or non-rechargables? I'm going to try these experiments in the charger I'm building to see what happens (In a large field with a fire extinguisher) If everything survives with the temp shutdown saving the day, then if I'm feeling destructive I may disable the temp monitoring to see the difference.

 

[cernobila]

Well, just pulled the trigger and bought another unit from "flashlightz" complete with the DC/DC unit. Took advantage of the fact that I am here in the US and dont have to worry about international postage. Now I will have one at home and one in my camping "kit".

 

[kurni]

No good, only charges two cells at a time.

Why can't I paralel 2 LiIon in 1 of the bay?

Thanks,
Kurni

 

[LuxLuthor]

Why can't I paralel 2 LiIon in 1 of the bay?

Thanks,
Kurni

If you can setup wires, you should be able to.

 

[LuxLuthor]

Is there a demonstration of what happens to a 3.0V cell in a 3.7V charger? or non-rechargables? I'm going to try these experiments in the charger I'm building to see what happens (In a large field with a fire extinguisher) If everything survives with the temp shutdown saving the day, then if I'm feeling destructive I may disable the temp monitoring to see the difference.

Many of the RC guys have pushed the crap out of the A123 cells, including overcharging which seems to have a main downside of reducing cell life (# of cycles) which is in one of the links in this post.

I think it is this one.

There is also a simple adapter "Dapter" ($40) which lets you use almost any Li-Ion charger with the 3.0V nominal A123 cells.

 

[cernobila]

If you can setup wires, you should be able to.

Lux, I didnt think you could charge four cells at a time with this charger, what would be the advantages and disadvantages of doing this.

 

[Mr Happy]

One advantage I could see with charging two cells in parallel in one slot is that it would halve the charging current per cell. Therefore if you have small cells like the 10440, you might feasibly charge them in pairs without exceeding the 1C safety limit.

The disadvantages of that would be that each cell in the pair would need to start out at approximately the same state of discharge (that is, equal starting voltages), and that good, secure, low resistance electrical connections would need to be achieved between the charger and each cell.

 

[DM51]

If you had (say) 4x 17670 to charge, you could either do them 2 at a time, or you could parallel them in pairs and do all 4 at once, with 2 wired to each bay.

Before paralleling them, you would need to check that the cells in each pair were at similar voltages, or you would get a rapid current surge on connecting them.

The disadvantage would be that charging would take longer, as only half the normal current would be going to each cell. You would not gain any time.

However, this would be a very good way to charge small-capacity cells such as 10440s, as they require a lower current.

Edit: I see Mr Happy has already said this - apologies.

 

[kurni]

Thanks Happy, DM51. I'm planning to charge 4 at a time because I'm going to use FM 4x14670 holder. I'll assume that all cells would be used at similar fashion. I'm not trying to gain any time, I just don't want to replace the batteries as I'll always need to charge 4 at a time.

Many thanks,
Kurni

 

[adamlau]

Re: PILA IBC Charger

Yes, my nut fits tightly on the bolt. I used brass. I don't know if it is the best, but I like brass, and it was available.

Odd, funny and somewnat confusing if you fail to review the previous comments first .

 

[Edwood]

You mean something like this?

http://xs128.xs.to/xs128/08271/p4195721162.jpg

Yup.



-Ed

 

[LuxLuthor]

Lux, I didnt think you could charge four cells at a time with this charger, what would be the advantages and disadvantages of doing this.

As the others have said. Remember that it is no problem putting Li-Ion cells in parallel (as long as their starting voltages are not far apart)...then to the charger, it appears as a single cell with larger storage capacity.

(You cannot parallel charge NiMH cells.)

 

[Burgess]

to AdamLau (Post # 54) --


:lolsign::devil:
_

 

[SilverFox]

Hello VanIsleDSM,

I just had another thought about the temperature monitoring...

I confess that I have not reviewed the circuit to see if this is how it works, so this will have to be checked out to see if it is valid.

There can be a safety issue if you start charging a cell that is hot from an extremely hard discharge. Perhaps the temperature monitor will limit or prevent the charge to begin until the cell cools off.

In a battery pack you may not notice a "hot" cell, so the temperature monitoring is important. However, when charging single cells for flashlight use, it would be difficult not to notice a "hot" cell.

Tom

 

[SilverFox]

Hello Adamlau,



Tom

 

[cy]

just found this most excellent thread!!! :thumbsup: