RE: Need opinions on what could be wrong
I am a plane guy but have had similar problems with esc’s
First off, is anything binding the motor/driveshaft/ect, this could cause the motors run out of phase (aka not run at all, just sit there and jitter)
Second make sure your throttle trim is down all the way
Third make sure your esc is “thinking” you have 10 cells (beeps ten times?), if it thinks you have 12+ cells that could explain the low voltage cutoff
Forth if you throttle slowly does it last longer? Maybe a few cells are bad (can’t hold high current)? Put the battery in another esc and try it?
if i had to guess your esc is assumeing you have more cells than you do, or you have a bad cell(s) which triggers the low voltage cutoff