Please make sure you do some reading about safe lithium battery practices before burning your house down, even with some protection you need to take good precautions!

This is a single cell Lithium Ion battery charger with protection circuit.

Micro USB connector for the power input, also has solder points if you want to apply 5v power directly, solder points for the Battery (B) and for the Output (OUT, cell voltage, not 5v).

This is a great board for using with unprotected 18650 cells as the protection is built in to the board - disconnects the OUT terminals off at approx 3A draw, or 2.5v minimum voltage.

Note that you may need to do a charge cycle to reset the protection circuit when connecting a new cell, otherwise no output would be drawn from the OUT terminals.

Remember that USB from a computer should not exceed 500mA, don't use this module with your computer USB ports unless you modify it to reduce the current as below.

The TP4056 Charge Controller IC implements a constant current - constant voltage charge, a slow pre-charge when battery is below 2.9v switching to normal charge once it's above this level. Also implements a soft-start to prevent inrush currents. Charging completes when the charge current falls to 1/10th of the configured rate (1A) once the 4.2v float is reached.

Two indicator LEDs are provided (charging, charged). Note that it does not provide temperature monitoring.

Do not connect the battery backwards or all the magic smoke will escape.

DIY Charge Current Mod

The charger is configured for a 1A max charge rate, but if you want to reduce that rate you can remove the resistor marked R3 and replace with another value, 30k = 50mA 20k = 70mA 10k = 130mA 5k = 250mA 4k = 300mA 3k = 400mA 2k = 580mA 1.66k = 690mA 1.5k = 780mA 1.33k = 900mA 1.2k = 1000mA (default) Max discharge is not configurable See all my listings: https://tinyurl.com/26tzbx6d