This is a “Lectric Longboard” (you can find their site through google), which is one of many of the Chinese clone boards.
The issue is when not plugged in, the board turns on as usual, makes the turning on noise, ESC fan turns on, but upon pressing the throttle up, the motor spins for 1 second and then the whole board shuts down. It works as normal when plugged in to an outlet. When the charger is removed while the throttle is pressed, it seems to work fine but only until you let go, as demonstrated in the video below.
I suspect that it is the BMS that is at fault here. The battery works on my brother’s board (which is the exact same board). Motor seems fine. In terms of electronics, I haven’t tried playing around with anything inside in an effort to avoid warranty issues.
I have been contacting support but they often take a day or longer to respond so I would be very thankful for any help from anyone really to get this board up and running asap.