Lithium battery fast charger circuit diagram

This circuit has a charging status display function. The red light flashes and is charging, the green light flashes and is about to be fully charged. The green light illuminates and is fully charged. As long as you have a 12V power supply, don't install the battery after connecting the circuit. Adjust the adjustable resistor in the lower right corner so that the battery output is 4.2V. Then adjust the adjustable resistor in the lower left corner so that the third pin of LM358 is 0.16V. That's it. The charging current is 380mA, which is super fast. The three parallel-connected diodes are step-down to prevent the LM317 from overheating, and a heat sink must be added to the LM317. The triode in the picture can be of any type.

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