The directions that came with the BMS are below. They are pretty straightforward. Looking at the black components on the board, I see a part number of HY5208, and I found this datasheet:
https://datasheet.lcsc.com/szlcsc/HU...8W_C330384.pdf And if I look on wikipedia for MOSFET (
https://en.wikipedia.org/wiki/MOSFET) it appears to be some sort of solid-state switching device. So I'm assuming the BMS switches off the current during charging or discharging as necessary.
The Chinese charger company refunded my money once I contacted them via PayPal, so I'll have to look elsewhere. I got a 50.4V 4A charger off Amazon today just so I'll have something to work with while I wait for another Chinese charger.
https://www.amazon.com/gp/product/B07T54J61Q
Next step is wiring the battery, the BMS, and the charger together.