Universal Single 3.7V Battery Charger Circuit
The Chinese universal single 3.7V battery charger is designed to safely and efficiently charge rechargeable Li-Ion (18650, 16340, 14500), AA, and AAA batteries with a voltage rating of 3.7V. It charges them to their nominal voltage of 4.2V while providing a steady current of 400mA. The charger incorporates a Bi-color LED that indicates the charging status, with the LED emitting a red light during the charging process and automatically switching to green when the battery is fully charged. Here, we will discuss and explain the workings of this 3V3 battery charger along with its circuit diagram .