LiFePO4 cell questions...

[shao.fu.tzer]

Forgive me if this has been answered before. But from what I understand the cutoff voltage of Lifepos is supposed to be 3.65 - right? Well, I bought a huge bundle of these lifepo 18650s off of fleabay and they're terminating at ~ 3.8 before coming to a rest at 3.73-.3.74 about 3-4 minutes later. Is this normal? Like 3.7 volts supposed to be cutting off at 4.2 but most show 4.21-4.22?



By the way, my charger that I'm using is an UltraFire WF-188, which is finicky, but I've had a lot of luck with (if you know how to use it right, it is extremely consistent).

 

[shao.fu.tzer]

Wow, this thread had at least 7-8 responses to it. I'm starting to see the havoc that was wreaked when CPF went down.

 

[KiwiMark]

For anyone reading this that doesn't know the answer - ~3.8V is too high and will shorten the life of the cells, but it is unlikely to be a safety concern and the cells will actually work fine (for a while at least). I'd recommend buying a better charger like this one: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7028 which will require some sort of power supply to run from mains (old laptop power supply, modified computer PSU or this). With a good charger like that you can charge all sorts of different batteries.

 

[brandocommando]

Here is how I do my LiFePO4 R123's, I charge them to 3.6V with no termination issues on the LiFe setting, and all 4 of mine have a resting voltage of 3.33V.
These must be good batteries!

P.S. they work awesome in my miniX, (although not recommended.)

 

[KiwiMark]

P.S. they work awesome in my miniX, (although not recommended.)

My AW 16340 LiFePO4 cells work pretty good in my Surefire A2, also not recommended but I don't care about that.