Li-ion Batteries: Built In Charge Protection?

[tommygdawg]

Hey all,

I've had a question for some time that I've had a hard time finding an answer to. If you have a Li-ion battery with built in charge protection circuitry, do you still need external charge protection? I have this battery: http://www.amazon.com/Fenix-ARB-L2S-Protected-Rechargeable-EdisonBright/dp/B00G9KHL4I

I was just curious as to the protocol with these kinds of batteries. Suppose you were to wire it to a small solar panel, would you still need external charge protection, since the battery has built-in protection? Any insight would be helpful!

Thanks!

[IanB]

The protection circuit is a last resort safety device in case other things have gone wrong. It is not a substitute for a proper charging circuit.

Lithium ion batteries like that one need to be charged with a lithium ion charger using a proper charging protocol.

[NiHaoMike]

I recommend charging to 4.1V at C/2 or less. Solar is an interesting problem to solve. Most standard charging chips are not usable, but there are a few that can be used, such as the LTC4070 for small panels.