I have an Engwei bike & it cuts out after a few minutes.
I have to stop & start again,
And so on! It's not the controller, I changed it. The battery seems okay.
No apparent worn wires. Open to advice.
I have no idea about those specific bike
but does it cut out totally - or are some lights (or whatever) still on and just the motor stops
might help to know maybe
if you can tell
good luck anyway
I have looked at the difference between torque & cadance sensors, but can't find any that tell me where it is & what it looks like!
Also, I changed the battery & it worked for about 5 miles, then started to cut out again!
This sounds like a battery or charger issue - have you tested the voltage of the charged battery?
Both batteries are at around 50v. Tomorrow, I'll charge the one in use & see if it works for 5 miles...... Then wonder what it could be!
A very common problem on early Carerra Crossfires (mine included) was intermittent, often frequent cutouts
Eventually found if I tape the battery securely to its mount / cradle, it doesn't do it, problem solved.
I guess vibration moves the battery around slightly, occasionally loses contact I suppose.
Have you looked on YouTube for any videos that might help?