Review on 🔋 SunFounder Power Supply Module for Raspberry Pi UPS with Rechargeable 5V/3A Lithium Battery Pack Expansion Board, Compatible with Raspberry Pi 4B 3B+ 3B/2B and 1 Model B+, Battery Not Included by Rory Kelley

The battery works well but you can get similar performance with a smaller battery which I have also used. The lack of a charging circuit seems ridiculous to me. It seems to have good features for my needs. I probably wouldn't buy this product again and would prefer a smaller battery pack. Update: The output voltage doesn't seem to be as stable as it should be. My Raspberry Pi 3 shows a low voltage warning about half of the time it is running. CPU usage never went above 30%, but even at 0-5% CPU usage I still see the low power warning. what to do with it TO UPDATE. I sent an email to Sunfounder asking for help/information on what I'm seeing but they didn't respond (thanks Sunfounder). I managed to "fix" the Raspberry Pi issue. I modified the battery management board to increase the output voltage to around 5.5V (no load). I tested my upgrade by setting the resistive load bank to 1.8A. It worked great! You purely voltage was >4.9V which would not trigger the low voltage warning on the RPi. My test with the RPi 3 showed the voltage drop to around 5.2V under "normal" conditions. If I really push the RPi I can get around 5.0V, but no less. If anyone wants to know more about this update let me know. It's pretty simple: you just need a 1 kΩ resistor, a piece of wire about 2 inches long and cut a few traces on the board.