U have so much info it’s easier for me to do this:
Ok, ran some tests using my clamp meter to read voltage and current on the 3 phase going from the Esc to the motor.
What I discovered is that the throttle does indeed control the amount of voltage that goes from the Esc to the motor.
More throttle=more voltage Less throttle = less voltage
if u hold the throttle till the motor fully spins up does the voltsge reading go down or stay the same?
With no load on the motor, the current draw form Esc to motor stays mostly constant regardless of the amount of voltage fed to the motor.
I ran these tests with 6s and 12s.
To my surprise, the no load current from Esc to motor was slightly higher with 12s.think that’s normal as its a higher speed with the 12s right?
1.3 amps at 6s
1.7 amps at 12s
There were momentary spikes in current during rapid acceleration.
And the current did increase substantially as I applied load by squeezing the wheel with my hand.
It did also seem that I was able to ramp up the current more when testing with 12s than with 6s.
Afterwards I went out for a road test, 12s vs 6s.
Climbing the same 10% grade
6s at full throttle went up the hill without slowing down
12s at maybe ½ throttle went up the hill with power to spare( 12s could have gone up faster but I was trying to keep same speed)great test isolating the voltage
Checking the temp of the Esc heat sink, the 12s run made it warmer than the 6s run.which test first? Maybe leftover heat? Actually this makes sense as esc work less on full throttle
Also to my surprise while going down the hill, the brakes seemed more effective and controllable with 6s setting could change this right?
I decided to run the road test again with an inline meter between the battery and dual Esc’s. The results are as follows:
Esc’s heat sink temps 84deg
Peak Amp draw from battery 37.38
Peak watts 863
Watt-hour use 1.9
Esc’s heat sink temp: 94deg
Peak amp draw from battery 18.4
Peak watts 898
Watt-hour use 2.1
It it makes sense that the 12s would use a bit more watt hours as it’s riding at a much lower percent of the no-load
All road tests where performed with dual TB 12s Esc’s and dual TB 6355/230kv motors 16/36 gears and 90mm wheels
After running these tests, I’m not so sure that 12s is such a good idea even with dual motors. Although higher voltage = less amps on the battery side of the Esc, it’s appears to be a different story on the motor side. **. its the trade off giving up low speed efficiency for the possible high speed and quick power. it’s worth it to me. Nice to see its not that inefficient considering how much higher the no-load is with the 12s than 6s. I’ll gladly give up a bit of range for the much greater top speed. **
I was not able to test current on the 3 phase during road tests but it did seem evident during bench tests that more voltage = more current, not less. Guess thats the difference between DC current and 3 phase AC current.
This could very well be the source of our problems with overheating Esc’s
The greater watt hours to get up the hill was pretty insignificant on 12s and the esc heating is likely the fact it’s being held to half throttle