Protected 18650 Micro USB Charger.

The module allows you to charge Li-Ion batteries (both protected and unprotected) from the USB port via a microUSB cable. Charging was assembled on the basis of a specialized charge controller TP4056. MicroUSB power is duplicated by contacts on the board.

Working principle:

When power is connected without a battery, the red LED lights up, and the blue blinks periodically.

When a discharged battery is connected, the red LED goes out and the blue one lights up - the charging process begins. As long as the voltage on the battery is less than 2.9V, the charge current is limited to 90-100mA. With an increase in voltage above 2.9V, the charge current increases sharply to 800mA with a further gradual increase to a nominal value of 1000mA.

When the voltage reaches 4.1V, the charge current begins to gradually decrease, then the voltage stabilizes at the level of 4.2V, and after the charging current decreases to 105mA, the LEDs begin to switch periodically, indicating the end of the charge, while the charge still continues with switching to the blue LED . Switching occurs in accordance with the battery voltage control hysteresis.

The rated charge current is set by a 1.2kΩ resistor. If necessary, the current can be reduced by increasing the resistor value according to the controller specification.

Red LED - indication of the battery charging process.

Blue LED - indication of the end of the battery charge.

Overcurrent protection is two-stage and is triggered if:
- load current exceeds 27A for 3µs
- load current exceeds 3A for 10ms

Input voltage 5V

Maximum charging current 1A

Charge Cutoff Voltage 4.2V +/-1%

Battery overdischarge protection 2.4 V

3A overcurrent battery protection

MicroUSB input interface

Size 27x17mm