YOUR CONTROLLER COOLING

Last weekend i blew up my modified controller. . first i drove to work and back...which is aprox. 110km
I used full speed and used about 40 Ah at 88V average. Then in the evening i had a party somewhere 10km further in town.
I drove full throttle and then...it stopped....i thought the circuit breaker was down so i clicked it on...BANG ! ZAPP !
Wow!...what the F..%# ?? Then i felt the Hub motor..it was cold...nothing...then i put my hand on the controller...Wooowwww

You could fry an egg on it !!

I never checked my temperature on my controller..not even when i first started to drove to work with it.

Back home i opened up the controller and saw the defective components. 5 pieces (which you couldn't see) o IRF4110 where shorted and two large caps 1000uF/100V went down. one 100n capacitor also was burned down. These were 63V types !! didn't see that coming...i allready drove 500km withit on 95V..

Now my next question is...I want to extend the FET's on the outside case with an external cooling plate which is cooled by extra cpu fans.

Did you allready build some kind of cooling system on your controller ? I could need some advice howto get the best cooling for my 12 FET's

I was searching for some cool profiles and came with this model:




The controller is 200mm width so i can attach this one on the side with use of a bar of metal which will transfer the heat to the element.
this element i can cool with 2 little fans which will be measured by a simple temperature meter from ebay.

I wouldn't extend the legs of the FETs. You'd risk shoot-through and kill the FETs again.
I guess, the controller got hot from a shortcut in one of the caps. That started a chain reaction.
IMHO there is no better cooling than there actually is. There maybe are some slight improvements like lapping surfaces and using silver grease. Or you could glue small heatsinks on the front of the FETs and put a small fan inside the housing to ventilate. But that's just minor improvements.

-Olaf

olaf-lampe said:

I wouldn't extend the legs of the FETs. -Olaf

Click to expand...

Hi Olaf



i am not extending the FETs to the outside. I just extend the heat disipation through a meat bar which is mouted on the outside of the controller.
i tried to draw a little schematic view..

Jeremy Harris suggested a way to mount mosfets which looks as if it could handle quite a bit of power. I haven't tried it yet but I am going to.

http://endless-sphere.com/forums/viewtopic.php?f=30&t=16728&start=75

Good thread, I have broken a lot of stuff in heat related "accidents"......I like airflow more than anything else.


I used to put my controllers in a bag with the battery.

That doesn't work. There is almost no air flow over the pannier in contrast to other parts of the bike.

Airflow is a free side-effect of movement and it happens to coincide with when the controller is working hardest. I always try to get as much air flowing over the controller as is possible.

There is also the option of using something artificial like a frozen pack which is wrapped up and left under or beside the controller

ok i tried another sollution which pretty works well for now.

I used this cpu heatsink and mounted it on the topside of my controller.
Also i placed a 60mm fan on the side of the controller. (these pics will follow)
I can put them on with a simple unused lightswitch on my scooter.



my temperature went from 60C to 35C...so that's very acceptable!

Good thread, I have broken a lot of stuff in heat related "accidents"......I like airflow more than anything else.

Click to expand...

I agree! While I was working out a system for my new 18 fet lyen controller I kept it in my side panniers. After a few miles it got to hot to handle! Simply mounting it in the open underneath my rack made the temperature come down to luke warm.

Actually it's not in the open. It's in a tupperware container. The tupperware container is sealed save for a switch that activates my lights, AND two airflow ports, one on the front and one on the back. They are each made out of two 90degree bends of PVC pipe. Airflow





I am more worried about the BMS on my ping pack. It get's wicked hot in my topeak bag. It doesn't help that the bag is insulated like a cooler! I'm going to have to put a heatsink on the bms, or pipe in some air to the bag. Or a combination of both!

Here a close up of the controller mounted on the scooter with cooler.

Here's my cooling, along with beefing up taces and replacing wires to 10AWG. All of this will cut down on heat.

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