is it ok to charge two rcr123s of differing levels at the same time?

[s.c.]

Hi, I'm ready to get some rcr123a batteries and a charger. At the moment, it'll only be used with my PD20 (possibly a PD30 in the near future) and so I'll only be using one battery at the time. So, is it safe to charge two batteries that are drained to different levels at the same time? Also, are there any dual chargers that will charge a single battery if needed?

Thanks. Any input would be greatly appreciated.

 

[foxtrot29]

As long as your charger has independent charging slots.

What charger are you going to be using?

 

[s.c.]

I was planning on getting this ultrafire. I'm open to suggestions...and a dual charger that can charge one at a time would be great.

 

[foxtrot29]

I was planning on getting this ultrafire. I'm open to suggestions...and a dual charger that can charge one at a time would be great.

Can't comment on that particular model.

I have the UF-139, and it seems to charge my rcr123's to 4.14. If I stick them (individually) in my DSD charger, they seem to go to 4.19. I don't know if this is because they are terminating due to the protection circuit (+ the error factor in my DMM), or not.

 

[LEDAdd1ct]

This may be over your budget for a charger, but I recommend the Pila.

 

[foxtrot29]

This may be over your budget for a charger, but I recommend the Pila.

I knew someone would! lol... Isn't there an issue with the PILA IBC for charging RCR123's though? I thought that it rammed the voltage in there a little to hard? lol

 

[mdocod]

I have the UF-139, and it seems to charge my rcr123's to 4.14. If I stick them (individually) in my DSD charger, they seem to go to 4.19. I don't know if this is because they are terminating due to the protection circuit (+ the error factor in my DMM), or not.

Yes, the WF-139 is running the charge up to ~4.35V without slowing down the charge rate. The PCB is terminating the charge before the charger is.

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As per the original question: As long as the cells are within ~0.25V of each-other when installed on a single-channel 2-slot charger, everything would be fine. Most chargers have 2 independent channels so this is a non-issue. The DSD chargers are single channel though, but are IMO healthier for li-ion cells (when they are working properly) than the various ultrafire chargers, which all seem to ramp cell voltage to ~4.3V or higher during charging of most cells.


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The Pila charger is ideal if you have a wider variety of li-ion cell sizes. I'd have a hard time justifying it if I were only charging RCR123s, the 600mA charge rate is a little over-kill for RCR123s, but it will drop into CV mode pretty quickly at such a high charge rate, so it's not completely terrible for the cells or anything.


-Eric