In January 2022 I found a cheap ebike for sale locally and bought it! The catch was that it had no battery. The previous owner had recently moved in from South America and wasn't able to ship the ebike's lithium ion battery, just the bike iteself.
The bike appears to be Vindrais Revol-E, retailing for about $1800 US.
The exsiting battery connector was snipped! This meant that even if I found an exact replacement battery, I'd have to do a bit of soldering to get the connections working again. I was curious at this point why there were two positive and two negative connections. My guess is that the middle two wires (the narrower ones) were for the headlight or the motor controller circuitry, while the outer, wider wires were for power delivery to the motor.
I googled around for what the control model might be:
No results for LSW1540
No results for X1911084884
Plenty of results for CE-G3M20211!
Power connectors look like bullet connectors, but I'm not sure what size
I think it's a controller for the headlight. Has connectors that look like JST-SM connectors (2- and 3-prong) based on this ebikes.ca page
Ooh! This looks like exactly the assembly on the back of my bike! Rear Rack eBike Battery 36V 13Ah 15Ah 17Ah 48V 12Ah 14Ah UPP Electric Biycle Bateria for 1000W 750W 500W 350W Bafang TSDZ2 Motor