I have a brand new Bestech HCX-D596 80A discharge + charge BMS for sale, new in package. First pic is from their site as my package is not open, 2nd pic is of the actual part. I ordered 2 to meet their minimum order requirement, and the one that I am using from the batch is working perfectly.
This BMS allows you to run your discharge circuit in a protected mode instead of just your charge circuit. It also includes a power switch circuit (although not the switch itself, so ignore the toggle switch in the first photo) so you can do without a loop key or 50 dollar anti spark switch.
Asking for 65 USD shipped CONUS