This is a “Powerbank” to be integrated into your Electronic Project.
With 2 Lithium Cells 18650 inserted, it delivers 2 different output voltages of 3V (max. 1A) and 5V (max. 2.2A).
The output voltage is available on several contacts on both sides of the module and also on a standard USB-A port.
To charge the Cells, a 5V USB power supply needs to be connected to the USB input (5V / 1A recommended).
There is a switch on board to disable the typically auto-off function of power banks: In “normal” Mode, the power bank will turn off the DC-DC converter on board after about 10s when the output current falls below 30mA. In “hold” Mode, the output will stay on until the battery is drained.