Unknown Li-ion battery packs... How to charge them?
Someone gave me several Li-ion battery packs (BobS can use anything...). They are all different, but all put out 7.6 V. Apart from the cells (4 of them, 2 x2 parallel), they are stuffed with electronics. They have 2 input wires (sockets), without a voltage rating on them. I already fried one circuit board with 15 V (thought it was 12 V....!!!). A model number Google search did not reveal anything. What would be the voltage to supply the battery packs??
I would like to take the cells out and charge them just like ordinary rechargables. Put them in battery holders for power tools and portable sound system (all have different volatge ratings).
Can I use the on board electronics (as is) to charge several ( more) cells in parallel?