Ho to charge a rechargeable battery?

[EliteGamer83]

I found a cell phone battery in my parts bin I got from an old phone which has long been turn apart, it's 3.6 same as the PSP and VERY small, I wanted to do a mod with it but it's out of charge. how can I re-charge it?

[P3nnyw1se]

What type, Ni-Mh or the other type...

[EliteGamer83]

3.6v Lithium Ion

[802Chives]

There is such a thing as a Lithium Ion battery charger, or google how to charge a lithium ion battery. I imagine a trickle charger would be fine, but you need to be careful because charging batteries can be dangerous if not done properly.(leaking cells or explosion)

The big problem with Lithium Ion type batteries is that they have a relatively poor shelf life, being that a 5 year old Lithium Ion wont perform nearly as well as a new one.  Everyone has seen it in their cell phone batteries after a couple years they are like 1/4 of what they were.