Review on 💡 Geekworm Raspberry Pi UPS X728 V2.0: Power Management Board with AC Power Loss Detection, Auto On & Safe Shutdown Function for Raspberry Pi 4B/3B+/3B by Evan Hernandez

This UPS meets most of my needs but I would like the Python2 scripts to control it to be updated from the manufacturer and if possible compatible with newer operating systems. After overriding a few things from the .py scripts provided on the wiki, it works enough with OpenWRT to query the battery percentage and do a controlled shutdown before the battery hits the low voltage cutoff, but I left it on "good enough", so I haven't got any power failure detection working there yet or 1 or 2 power button functions. One odd thing I noticed about this UPS is that the battery percentage fluctuates when running on AC power. When I first put the (brand new) batteries in, I noticed that they were 100% charged, then the controller goes into a kind of discharge cycle that takes it down to almost 90%, then charges back to 100% and repeats . again and again. From what I've read lithium should be fine in that range and hopefully daily repeated cycles won't wear the battery down to just the top 10% charge after thousands of such cycles. Maybe the charge controller needs a full discharge/charge cycle to know the capacity? More research is needed, but they are all brand new balanced cells. I've had a few brief power outages over the past few months, but it wasn't enough to test full runtime on 4 connected 18650 cells. I reckon, to spend a few hours just booting up the Pi and a couple of USB network adapters. There are other UPS solutions for the Pi that can be scheduled to boot at specific times.