UPS HAT (Uninterrupted Power Supply)
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Uninterruptible Power Supply (UPS) Allows for the safe and orderly shutdown of single-board computers and any attached hardware" A UPS, similar to the UPS backups used in our homes and businesses, may be built to save the Pi during power outages or unintentional shutdowns. This UPS HAT can offer enough time to store the code on the RPi and can also be used as a separate power supply unit for backup... 
It is capable of effectively charging the batteries and providing power output from an external power supply. If the external power source fails, the UPS HAT automatically switches to battery power, keeping the system functioning smoothly. It is compatible with all Rock SBC, Raspberry Pi Series boards (Standard 40 PIN GPIO Header), Banana Pi etc.