Review on MakerFocus Raspberry Pi 4 Battery Pack UPS, RPI Pack V3 Expansion Board Power Supply Type-C for Raspberry Pi 4B 3B+, 3B 2B+ with USB Battery Pack Raspberry Pi Support by James Hardy

I loved this power module but it has two downsides, one serious, the other not so serious but still an oversight. The first big one: It doesn't have under-voltage protection for lithium batteries. If you leave your Pi on, it will eventually turn off, but will not shut down the circuit to protect the battery. You can see the LEDs pulsing as he tries to stay alive, the voltage is well below what he can handle. The main problem is that this will completely destroy a lithium battery if you let them do it more than a few times as they don't take a deep discharge. I measured the cell after leaving it on overnight and it came out at 2.78V. The second issue is that it powers your Pi and also plugs into USB for charging (which it does if you connect a 2.5A source). If you disconnect the charging source, the Pi will lose power for a short time, causing a reset. I have a feeling this can easily be solved by a circuit engineer. If you're just looking for a battery pack for your Pi to keep it going for hours, it will do the job perfectly, but don't plan on leaving it idle on battery power as it will eventually kill its own battery from over-discharging . . . EDIT: The manufacturer contacted me and said they reworked the board to fix both of these issues and sent me a new one. Now it won't turn off when disconnected or connected. Also, when the Li-Po drops to 3.2V, the circuit will be properly broken.