how to fan cool a controller?

Electric Motors and Controllers
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izeman   10 GW

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how to fan cool a controller?

Post by izeman » Jun 28 2013 4:56am

i want to see what my eb312 is capable of. it's got 4110 mosfets, so in theory some more amps then the standard 40A should be possible.
first step: beefing up the traces with thick wire. easy.
second step: maybe adding a third shunt. easy
third step: active cooling. not so easy.

how could that be done? normally you would to a side2side cooling. inlet at the cable side, and some holes at the opposite side.
but as the controller is only a bit more than an inch high/25mm the fan would be super small. we all know that 20mm fans are toys. not fans in a common sense ;)

so i could make a 60mm hole on top of the case and add holes on each side so air is sucked in in the middle above the controller board, and blown out through the little holes at the side.

as the controller is mounted where enough air passes it, it's also in a position where mud and rain can easily reach it. not that i intend to ride in the rain, but you never know what happens during a long tour.

Image

any ideas what to do? the position of the controller itself is NOT negotiable ;)

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mlt34   100 kW

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Re: how to fan cool a controller?

Post by mlt34 » Jun 28 2013 5:18am

Can you move the controller?

Just kidding :-D

Have you considered passive liquid cooling? Filling the controller with cooling oil (there are a few types for a few price ranges) and then sealing the controller liquid tight.

The extra thermal mass of the oil first absorbs excess heat and then secondly it serves to transfer the heat to the aluminum case via convection much better than the air did previously.

It could be a simpler and safer option. Just requires sealing the controller well to prevent leaks.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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izeman   10 GW

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Re: how to fan cool a controller?

Post by izeman » Jun 28 2013 5:29am

hmmm. oil cooling could be a good idea. but i HATE the mess if you ever have to open it. also sealing the cable ducts would be a nightmare.

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Re: how to fan cool a controller?

Post by John in CR » Jun 29 2013 1:01am

If you plan on riding in the rain, you shouldn't have your controller like it is in the pic. The wiring harness will act like a channel and water will follow it like a river channel directly into your controller.

For touring forget about ventilating your controller. Low stress and dependability is what you want, so if you need more current simply run a 15fet or 18fet controller.

Ventilating is easy with the controller horizontal. At the intake end bring tubes from below the controller so things will have to travel up hill to enter. Intake tubes also enable you to direct the flow toward the fet bar. Just be sure they aren't too restrictive and prevent air flow. I've used fans similar to these 40mm blowers http://www.alibaba.com/product-gs/81558 ... lower.html. They are a tight fit to mate with a large hole in the rear cover of the controller. Just seal well around the edges and orient the exhaust so it is low or angled downward so nothing enters through the fan which will be sucking air in from the other end of the controller. I've used this method on several controllers that needed extra cooling and it is effective. I stuff 425A batter side 550A phase thru a 36fet controller using a 40mm blower to help with cooling.

John

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Re: how to fan cool a controller?

Post by Lebowski » Jun 29 2013 4:46am

Have a look at the pictures in the big lebowski controller thread. I use a blower instead of a fan.

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mlt34   100 kW

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Re: how to fan cool a controller?

Post by mlt34 » Jun 29 2013 1:52pm

izeman wrote:hmmm. oil cooling could be a good idea. but i HATE the mess if you ever have to open it. also sealing the cable ducts would be a nightmare.
How often do you open your controller now? Most people never have to go playing around in there. Also, your wires exit up, so you wouldn't have to seal them that well, just some light siliconing dabbed on there should do it. Basically just enough to keep splashing water from getting in, though with the wires oriented up like that, a little silicon there is pretty much already a good idea. You'd only have to seal the bottom really well to keep oil from seeping out of the joint between the bottom plate and the main aluminum box.

I've always wanted to do this but I've never pushed a controller to its limits enough to need it.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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fechter   100 GW

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Re: how to fan cool a controller?

Post by fechter » Jun 29 2013 2:58pm

Your controller seems to be mounted in a position that's nearly ideal for passive air cooling. I don't think adding a fan will improve it much unless you spend a lot of time riding really slow.

Does it get hot?

Another option might be to simply add more fins to the heat sink to take advantage of the natural wind.

If it does get hot, you could mount a fan to the flat side (front) with some spacers so there's room for the air to circulate. This way the controller can stay sealed, but the fan would be external. You would probably want a screen or finger guard to keep rocks from hitting the blades.
"One test is worth a thousand opinions"

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h0tr0d   1 kW

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Re: how to fan cool a controller?

Post by h0tr0d » Jul 01 2013 3:41pm

Oil filling a controller probably isn't the smartest idea...

http://endless-sphere.com/forums/viewto ... 53#p749552
Thank you Justin! Life is so much sweeter with this forum... ;)

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mlt34   100 kW

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Re: how to fan cool a controller?

Post by mlt34 » Jul 02 2013 2:40pm

h0tr0d wrote:Oil filling a controller probably isn't the smartest idea...

http://endless-sphere.com/forums/viewto ... 53#p749552
why not, from your graph it looks like the EC+oil was a big improvement from stock, and a decent improvement from just water filled.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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izeman   10 GW

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Re: how to fan cool a controller?

Post by izeman » Jul 04 2013 2:51am

Kathy wrote:It got me,why the controller cann't get cool by itself?Do you all use a fan to cool down the controller?Confusing :shock:
i don't understand your question. sure i cools down by itself. it's all a matter of voltage, current, wind speed and ambient temperature. take it to the limit, and active cooling helps. or buy the next bigger controller. the only two choices you have.

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h0tr0d   1 kW

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Re: how to fan cool a controller?

Post by h0tr0d » Jul 04 2013 10:06am

mlt34 wrote:
h0tr0d wrote:Oil filling a controller probably isn't the smartest idea...

http://endless-sphere.com/forums/viewto ... 53#p749552
why not, from your graph it looks like the EC+oil was a big improvement from stock, and a decent improvement from just water filled.
Sorry mlt34, you are right. For MY application oil filling isn't very good. Perhaps for Izeman it's enough...

Off topic: Your ebook covers mid drive conversions?
Thank you Justin! Life is so much sweeter with this forum... ;)

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mlt34   100 kW

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Re: how to fan cool a controller?

Post by mlt34 » Jul 04 2013 11:42pm

h0tr0d wrote:
mlt34 wrote:
h0tr0d wrote:Oil filling a controller probably isn't the smartest idea...

http://endless-sphere.com/forums/viewto ... 53#p749552
why not, from your graph it looks like the EC+oil was a big improvement from stock, and a decent improvement from just water filled.
Sorry mlt34, you are right. For MY application oil filling isn't very good. Perhaps for Izeman it's enough...

Off topic: Your ebook covers mid drive conversions?
My book does cover mid-drives but not in as much detail as hub motors. It's really designed to be a book for people building their first eBike, and so while mid-drives and their advantages/disadvantages are discusses, I recommend to first time builders to go with a hubmotor on their first bikes to learn about ebike building/ownership before attempting a more complicated mid-drive build. I provide more resources for people still intent on exploring mid drive in their first ebike.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: how to fan cool a controller?

Post by John in CR » Jul 05 2013 4:17pm

izeman wrote:
Kathy wrote:It got me,why the controller cann't get cool by itself?Do you all use a fan to cool down the controller?Confusing :shock:
i don't understand your question. sure i cools down by itself. it's all a matter of voltage, current, wind speed and ambient temperature....
You left out possibly the biggest factor, which is the motor and how it is geared. Speed wind hubbies for example, generally have low inductance in the phase windings which is more difficult for controllers to drive and results in more controller heat. Motors geared for high speeds end up running at low duty cycle much of the time, which is also hard on controllers because it results in higher phase current multiplication resulting in more heat in the controller.

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Re: how to fan cool a controller?

Post by spinningmagnets » Jul 12 2019 10:13am

I would use two server-computer fans that are designed to run off of 48V (one pushing, one pulling). For a 72V system I would run three 24V fans in series. The centrifugal style will push more air than an axial, and look for a fan model that has ball bearings.

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izeman   10 GW

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Re: how to fan cool a controller?

Post by izeman » Jul 12 2019 11:46am

spinningmagnets wrote:
Jul 12 2019 10:13am
I would use two server-computer fans that are designed to run off of 48V (one pushing, one pulling). For a 72V system I would run three 24V fans in series. The centrifugal style will push more air than an axial, and look for a fan model that has ball bearings.
Really? One of my first thread in 2013 got a reply in 2019? ;)
Just out of curiosity, what made you answer this NOW?! 8)
Btw: The build is discontinued for a long time now ...

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spinningmagnets   100 GW

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Re: how to fan cool a controller?

Post by spinningmagnets » Jul 12 2019 1:59pm

Ha ha! I didn't look at the date...

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izeman   10 GW

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Re: how to fan cool a controller?

Post by izeman » Jul 12 2019 3:11pm

spinningmagnets wrote:
Jul 12 2019 1:59pm
Ha ha! I didn't look at the date...
:bigthumb: 8) :lol:

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