Cooling the ESC


Oh, forgot about the erpm limitation, right!

IIUC there is an inherent problem with creating low KV inrunners, right?


It is in progress right now. APS has a ‘powerglide’ motor, which is a 100kv 4kw 5684 (iirc) inrunner. It JUST came out, but the issue is just that there hasn’t been a need to develop motors in that size, kv, and power until now.


Well, the VESC6 has a limit of about 150kERPM, so 500kv is really at the limit (the SSS uses 6poles) but anything below will be fine…


the 150kerpm is burst. I have significant doubt for holding a 150kerpm for any duration of time longer than a few seconds at most. Not to mention the VESC6 is $300+ and there just aren’t enough people testing it for reliability.


@cwazy1 where have you seen a 100kv INRUNNER from APS ? I can only see the Outrunner one.



@cwazy1 I’d probably agree about the eprm, I’m not sure what real world testing has been done…here’s a test on a vesc6 clone ‘ESCcape’


Use a diaphragm pump. They are quiet, self-priming and can run at 5V, should be used together with a filter on the inlet side to remove debris.

The ESC with some heatsink to it can run almost without cooling (takes 10 min before overheating). so the water flow needed it not very high, we have good results with the pump above. Altho you need to rinse the system after use to prevent salt blockage in the tubing.

the rinsing is easy when you use a pump, its more tricky if the system is pressure based.


I use a closed system with a cheap pump from a windscreenwiper. Asssuming power use is 2Kw and the losses in the esc is 10% ->. heatingpower is ,2Kw. It will take 33min to heatup 1,2L water 80 degrees. Water volume then has to be adjusted by trial and error. If the esc efficency is a lot worse it will not work.


How big battery pack are you using with this? I have the parts for a closed loop system as well, also a aluminium heatsink that can dissipation heat from the water. Nice to not need flushing of the system, but 1.2 L gives some extra weight tho.


I used to run it on 4 AA batteries since the pump dit not need to spin at full rpm, it did last for a few sessions. Now I have a bec with adjustable voltage from Hobbyking. The good thing is you do not have to think about priming the pump and no worries with dirt. The water volume can be reduced if there is som dissipation in thee system.


Hiorth, what thermostat switch do you use to control the water pump? At what temperature do you switch on? Or is the pump running continuously?



Thank you Hiorth, I’ve ordered one. Lucky me I heard a mini peristaltic running:-:fearful: not on the quiet side! Thumbs up for all your development, an max respect for you guys that still riding in January in Norway! I’ve been there lately and I won’t even dare to touch the water!!


We have a 40C switch connected to the heatsink on the esc. But works well with continuous drive as well.


jeffM, could you send a link to the box which you’re using?



I can not find the piece in the trade to pass my cooling pipe through the waterproof box, can someone inform me? thank you


I’m still seeking the same! With no luck so far


On way is to use a regular cable glad. To make sure the clamping force of the cable glad does not pinch your cooling-tube, add a metal-tube through the glad, then attach the cooling-tube on both sides of the metal-tube.


very ingenious, thank you for your answer


2-3mm internal diameter silicone tubes fit tight (very tight) on PG7. Pass thru, with no metal pipe junctions. I found the barb head junctions on ebay. Com but not in Europe. So it will be PG7!