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Charging Recycled Li-ion Batteries Answered

I have busted mp3 players that I've already thrown away but decided to keep the Li-ion batteries in them for future use. Now i tried to connect them to LED's to turn into flashlights and they worked perfectly. Now the main concern is if i will use them as batteries for my flashlight how will i be able to charge them?

Can I replace the jacks of the mp3 players' original charger with bulldog clips and just connect them to the terminals of the Li-ion batteries to charge them or do i need to connect a simple circuit for the Li-ion batteries?


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9 years ago

I believe that Li-ion batteries need some sort of control circuitry when recharging.

Pop the case off the charger, and have a look inside. If you can only see a rectifier circuit (capacitors and diodes), then the control circuitry was probably in the MP3 player. If there are other electronics in there (maybe transistors or chips), then you may have the control circuitry in the charger.

If in doubt, take an in-focus macro shot of the innards, and post them here so somebody can check for you.