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General Discussions / Re: Air Cooled vs Watercooled BLDC Motor
« Last post by Bikemad on March 19, 2024, 12:45:24 PM »Let’s say the controller was getting too hot, how would I cool it down? I have the VEC500
Check out this post for more information on cooling the controller.
Also, for what it’s worth, there seems to be a safety mechanism in the software that remembers the lowest amp draw you pulled while overheating. Next time I took the boat out, I couldn’t pull more than 119 amps which is where it was when I overheated it last. It gradually stepped down to that level over a ~30 minute period.
According to the programming software, the motor temperature will cut the current back to "Level 1" when it reaches 120°C and "Level 2" when it reaches 130°C.
If the motor temperature exceeds 150°C, it should stop the motor completely.
However, the value that really puzzles me is the "Motor temperature protection exit value" which seems to be very low (20°C).
Does this really mean that full current (or any motor use, if it had cut out completely) would not be available until the motor temperature had dropped below 20°C?
The next time I took it out when the motor was cold, the amp draw slowly increased the more I ran it. By the time I was done running it at max throttle for about 5 or so minutes, I was pulling 123 amps. This tells me it’s stepping the amp draw back up for as long as it’s not overheating.
Something else to consider might be the battery itself, as its power output can also be affected by temperature.
If it is too cold at the beginning of the trip, you may find that it cannot deliver the expected current until the cells have warmed up sufficiently.
The battery's state of charge will also affect the amount of voltage sag under load, which could cause a dramatic drop in power if the voltage at the controller falls low enough to trigger the controller's low voltage protection, which I think is set to 44V by default.
If you want to monitor the voltage drop under load, you should attach your voltmeter leads to the B+ and B- terminals on the controller.
Let's hope that you are able to get the battery current back up to 200 amps again.
Alan