Just uploaded a video to my channel with my new self-powered power shelf that I'm using to test the 20P groups I'll be using in my final battery packs:
I use one 4S20P pack to power an iCharger1010B+ and that in turn charges/discharges 1S20P groups to get capacity figures. It takes about 25%...
The Tripplite sine wave inverter I am working with is supposed to handle up to 16V on the input:
I'm planning to test that with a 4S li-ion battery pack run at 4V/cell.