The TP4056 chip li-ion battery charging module has a low cost and it can easily charge your rechargeable cell with a current of up to one ampere. It is very convenient that this scarf has a micro-USB connector and therefore connects via an ordinary USB cable directly to a charger or computer / laptop, that is, you do not need to have any specific power supply.
This module also has protection against overdischarge, overcharge and high current. The protection threshold for excessive discharge is 2.3 - 2.5 V, the overcharge charge is 4.2 - 4.3 V, and the maximum current is 3 A. If you do not need such a protector, then the battery can be connected to the charger without it.
Since batteries have different capacities and each of them should receive a certain current (usually for 1C lithium-ion), the manufacturer of the 4056 chip took this into account and therefore you have the opportunity to adjust the current by changing the value of the resistor. Below you see a table by which you can select the charge current you need. You can install a tuning / variable resistor and it will be very convenient to change the output current without soldering.
After power is supplied to the charger board, the blue LED lights up and the red blinks quickly. Immediately after connecting the charged element, only the red light-emitting diode will be activated - the charging process is ongoing. After reaching the battery voltage of approximately 4.2 V (+ -1.5%), only the blue LED will remain on, which indicates the end of the charge, the bank is fully ready for further operation. During the charging process, the integrated circuit heats up a little with high currents: with prolonged use, it is better to fix the printed circuit board to the radiator.
Cost: ~ 24