This UPS lithium battery expansion board is specially designed for Raspberry Pi, it has two working methods, outdoor portable, and UPS power supply indoor. When working indoors, the board can only be powered by a lithium battery, the max power supply is 5.1V/2.5A. When working indoors, plug the normal 5V/2A power cable into the MicroUSB interface, then the max output power from USB-A interface will be 5.1V/3A. The board can be used to discharge while charging, the UPS power off doesn’t affect output external power supply.

There are 4 LEDs on the board that is used to estimate the electricity of the lithium battery. When the four LEDs are on, means the voltage of the battery is up 3.9v, the battery capacity is between 50%-80% when three LEDs are on when two LEDs are on, means the battery capacity id between 20%-50%. You should charge to the UPS when there is only one LED left. This UPS power board integrates overcurrent, over-discharge protection, with a self-recovery fuse to the external output, to avoid Raspberry Pi being burnout because of the external short circuit. In the application of high power, in order to prevent the Raspberry Pi from showing the lightning symbol due to the line loss lowering, there is an EXT power supply port on the board. You can supply the Raspberry Pi directly through DuPont line to avoid the internal resistance of the USB line to solve the line loss reduction. Connect your lithium battery to the UPS expansion board, just turn the UPS switch to the ON position to power the Raspberry Pi from any USB port. The power light is always on, and the 4 LEDs will be on and turn the switch to the OFF position to stop the power supply.