LiFePO4 charger capable of charging reg. Li batteries?

[FlaverSaver]

I've been using Tenergy 3v 750mah RCA123 LiFePO4 batteries in my setup for a while, but noticed they were starting to require abnormally frequent charging. So I purchased some new Tenergy 3v 900mah RCA123 Li batteries online. But my issue is that the LiFePO4 charger supplied with the respective batteries doesn't charge my new Li batteries, although they fit. Is this common? Should I be aware of some danger..? Or does anybody else know what could be wrong?

 

[Hambone68]

FlaverSaver, did you actually mean regular Lithium batteries, or rechargeable Lithium-Ion batteries? Regular lithium batteries can't be recharged - trying to do so may result in nasty consequences (i.e. explosion, fire, etc.) so definitely don't try to do that! I'm not sure if a LiFePO4 will be able to charge a Li-Ion battery, it depends on the specific charger. For more information about different types of battery chemistries (and really good info about safe charging) check out Battery University - you should be able to find out anything you need to know there. There are probably also other threads here on ECF that will be able to point you in the right direction.

 

[FlaverSaver]

Thanks. Yes, they're rechargeable Li's, my mistake. Just not LiFePO4's

 

[slimest]

The main thing - charging current of your LiFe charger. Sometimes these chargers use very high charging currents for fast charge. In common you have to charge your new batteries using current no more than 1 capacity. I.e. if your accumulator, say, is 1600 ma-h, charging current should not be more than 1600 ma, better less.
If the current fits this rule, you can charge usual li-ion accumulators, but they will be not fully charged because LiFe accumulators have less voltage to charge. It does not damage the batteries, but you cannot get the full energy from them.
P.S. But never, never charge LiFe batteries with chargers made for usual LiPo batteries - you will destroy batteries.

 

[cappadoc]

The Tenergy 900mAh 3 V batteries are regular Li Ion's with a diode to lower the voltage to 3V. They require a dedicated charger that is around 4.4V, I believe. You CANNOT use a Li ion or LiFePO4 charger with these!

 

[FlaverSaver]

Baaaaaaah! Now I need a new charger. Thanks a bunch folks, that was a head scratcher.