Ever since I downgraded from the 650A to the 550A model controller, it hasn't been able to keep up the continuous power handling with no water cooling. I happened to have some PC liquid cooling parts lying around, so I thought I'd give them a whirl. The radiator is hilariously small, but it's better than nothing.
First, the tube diameter was not the same for the chill Curtis chill plate and my CPU cooler, so I had to adapt it:
I'm zip tying things in place for now while I test to see if it's even worth it:
I the pump has a nice mini built in reservoir, and it is supposedly rated at 0.4A at 12v, so ~5 watts of power consumption. It seems to move the water pretty fast for what it is. I hooked it up to my 30w solar panel on top of my battery box, and it runs it full speed even in intermittent sun. At night, I have a 12v aux switch hooked up to run it off my aux battery.
I took it out today, and it's night and day difference. I imagine most of the improvement comes from doubling the surface area on the heatsink. I had the controller bolted up to the chill plate with nothing running through it before, and now it's got water contact as well as actual flow. For now, the mini radiator is doing passive cooling and gets its airflow from driving.
Not having to worry about controller limits as much, I adjusted some controller parameters for improved acceleration rate and doubled my regen. I also discovered that I never set the RPM limit to 8000 when I downgraded controllers... it was set at 7500. So now I can hit 50 mph in 1st gear, and I hit 70 mph going up hill in 2nd. I rode around beating the piss out of it starting in 2nd gear doing max throttle runs repeatedly for a stress test. While I never hit thermal cutback on the motor, I got home and hooked it up to the monitoring software and discovered the motor was at 108C
The controller was sitting at 45-50C.
So... let's just say that the AC-20 motor is not sized for a 1240 lb car to do continuous highway driving. The power is definitely there, but I need to cool this thing. Since I already have cooling running in the back, I was thinking about getting some copper coil pipe, wrapping the motor with it, and then sending the coolant through that. I'd obviously need a way bigger radiator and a powered fan on it, but I'm thinking I might boost the motor's capability to handle continuous highway driving. Thoughts/comments welcome.