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VESC limits power after 15 sec

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Last seen: 1 week 1 day ago
Joined: 2022-02-16 12:58
Posts: 2
VESC limits power after 15 sec


I have just finished making my second e-foil. But now I have encountered one problem, where I need your help.
When I give full throttle, it takes about 15 seconds before the motor makes a strange sound, and I lose a lot of power. If I let the throttle down to about 70%, the sound is gone. I have to let the board sit for about a minute before I have full power again.
I gradually lose power from when the VESC is about 40c, and it gets worse the hotter it gets. I have set the temperature cutoff to start at 80c and end at 90c.

I also have problems starting the motor when it is stationary. 50% of the time, it just makes a sound and stopps. I don’t know if this is related to the other problem
I have set the number of motor poles to 6.

My settup:

-Spinted 80V 100A (it is now named 85V 150A, same hardware)
-Flipsky 65121 motor (130 kv) (filled with mineral oil)
-16s 1p 4680 cells (30ah each, 1776 Wh total)
-Daly 16s 100a BMS
-maytech remote
-PETG proteller, Diameter: 6inch Pitch : 7 inch, to blades

This is my VESC settings:

-Absolutt max current 200a
-Motor current max 135a
-battery current max 98a
-battery voltage cutoff start 52v, end 48v
-MOSFET temp cutoff start 80c, end 90c
-Acceleration temperature decrease 0% (tried 15% )
-Duty cycle 96% (i get to 50% on static thrust test)

I have tried the following things:

-set “Acceleration Temperature Decrease” from 15% to 0%

-smaller propeller

-checked that I have a constant voltage of over 60v under load

-checked that the phase conections to the pluggs are cool to the touch under load

-upptated to the latest VESC firmware

-changed motor current to diferent values

-changed temperature limits to diferent values

I really appreciate all the help I can get! looking forward to having two oprative
e-foils :smiley:

electricfox's picture
Last seen: 4 hours 38 min ago
VESC Original
Joined: 2019-01-01 17:11
Posts: 98

Looks like your motor has no temperature sensor. Maybe it overheats or some bearings are not fine and make it turn harder. Uploading a log, motor and appconfig XML´s would help analyzing your problem.

Last seen: 1 week 1 day ago
Joined: 2022-02-16 12:58
Posts: 2

The motor is filled with mineral oil, and is driven in the water which is about 6°C overheating therefore seems unlikely.

a bad bearing is a nice suggestion, I will try to swap parts with my other e-foil, and eliminate the problem.

I will try to upload a log, and VESC setting