PiPower not working?

When you put the battery in for the first time or when the battery is unplugged and put in again, the battery will not work properly.

This is because when the battery is removed, due to the mechanism of the on-board over-discharge protection circuit, the voltage will be considered too low, thus activating the protection circuit;

At this time, you need to plug the Type C cable into the charging port to release the protection circuit, and the battery can be used normally.