Simple USB DIY Li-ion battery charger circuit

arup shared his USB DIY Li-ion battery charger circuit in the project log forum.

The circuit uses both op-amps of an LM358 to control the charging of a single cell lithium ion battery. Charging automatically stops when the battery is full, and it is possible to charge batteries that have gone below the undervoltage limit. Power is provided through USB or any other 5V source.

Via the forum.

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14 Comments

  1. send me circuit diagram for single cell and double cell li ion charger using lm358
    and other if available.
    thanks

  2. Is this for battery packs or for single cells ?? (single cells that are not attached to any circuit).

    thanx for the link!!!!

  3. may I know what software for pcb board I use LiveWire or Proteus but no component for usb and battery.. can u help me as soon as possible. Thank you

  4. Can you please send me the schematics of the above Lithium battery charger using the lm358N op amp
    I am having trouble with other idea’s I have tried off the net charging 8.4 volt Batterys resulting in there distruction

    Thank you

    1. Please don’t. Always get a balancing charger for multi-battery packs. Even for a single cell or an isolated from a multi-cell pack, you’re better off getting a charge board with a dedicated chip, look for TP4056 boards for instance. Charging ICs have a 4.2V end point with 1% precision or better. This thing does not even have a trimmer pot. I also don’t see any current limiter, relying on the USB port to current-limit. Lipos can go boom, you say “resulting in there distruction” yourself so why continue to do risky things? Better maximize safety first…

  5. Please tell me how this circuit works . . step by step . . specially how these 3 LED’s work using op amps . . and how to get a feedback from the battery to the op amps . .

    1. Strange message these, they seem to pop up here and there, with little follow-up. Them real people or what?
      Well, a word of friendly advice, if you can’t find it in the above, then I recommend instead that you spend a few hours carefully researching Li-ion charging. Remember to look for accuracy, precision, and the SAFETY aspects. Simply cribbing a circuit from the Internet CAN BE DANGEROUS. Don’t blame us if your house burns down, alrighty?

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