How do you water cool a water cooled ESC?

[Dauntless]

I feel like I'm asking "What do you do with a drunken sailor. . . ?'

But I'm serious, how do these water cooled controllers work? This one is for RC, which is working towards becoming synonymous with electric bikes. I've never found anything about making it work that makes sense to me. Is it only for RC boats? (Found videos of them sucking water from the lake.) Do you think this oh so inexpensive 120 amp controller will melt without the cooling?

http://leaderhobby.com/product.asp?ID=9394001220127

And Karmabike1 said something about "Doc" in another video. I don't think he's Bugs Bunny so I'm thinking this video has been up here before.

[youtube]oPDVQAmrSX8[/youtube]

 

[fizzit]

There are two barbs on the ESC, one that you pump cold liquid into, and the other one the warm liquid comes out of. It's just a set of tubes stuck on to the ESC instead of a normal heat sink.

 

[Dauntless]

The point is, I'm assuming it has it's own water pump, but is there an actual COOLER available? Is it intended just for a boat?

 

[stingray17]

No, that controller probably does not have its own pump. And yes, that one is intended for a boat, but that is not the only way to use water cooled motor controllers. If you want to do water cooling, you could use equipment designed for a boat, but wouldn't necessarily have to. You could also buy or make a "water block", which is basically a hollow chunk of metal with tube fittings, and use it to replace a heat sink (passive or fan-cooled) on existing equipment. Then what you would do is create a closed-loop system that pumps water through the ESC. The water gets heated as it goes through the water block, and the warm water gets cooled off, then pumped back in.

So, the other needed parts for a water cooling system are a water pump, radiator and reservoir. These are typically separate although you can find combo units with 12V pump+reservoir+radiator all in one (see link below for examples). Also fans are sometimes used to cool the radiator, though on a moving vehicle that might not be needed.

Water cooling is typically more complicated than air cooling, using more parts and often more weight and size too. But still it may still have some possible advantages in certain situations, and here they are:

* The water block can be very small, while the radiator can be much larger. A water cooling system will "spread out" the heat from a small hot area over the large area of the radiator, where it can cool down quickly even in slower-moving air.

* Heat dissipation can happen away from the source of heat. So you could for instance have your controller hidden away (like in a sealed box) but pump its heat out to a radiator that is exposed.

* In general you can move away more heat from your components quicker, using a water cooling system instead of using heat sinks with fins. This might allow you to put more power through a controller before it starts melting...

* If you have to choose between water pumps or high-flow fans, water pumps are generally much quieter.

Water cooling is sometimes used on high-performance computers to efficiently and quietly remove waste heat from their high-powered CPUs and graphics cards - these chips can often put off well over 100W of heat from an extremely small surface area. PC water cooling components are often overpriced, but water cooling is the kind of thing where you can conceivably build your own. If you are curious about water cooling you might consider browsing PC cooling parts just to get some ideas. Here are some (not plugging the vendor but they do have a well organized site for browsing) http://www.frozencpu.com/cat/l1/g30/Liquid_Cooling.html

 

[Hillhater]

Unless i am mistaken ( it happens frequently ! ),.. that video is simply showing a water pump ( in the box) being controlled by the motor controller ( on the bike) ?

 

[Dauntless]

There's a part I video that's not even as good as this but it did give me the idea that there's no external pump, I assume it's in the ESC. But maybe I misunderstood.

 

[jtchoy]

As mentioned by fizzit, water-cooled ESCs for RC boat use just has a "heatsink" with barbs for cool water to go in and hot water to come out, removing the heat from the ESC.

RC boats have a water pick-up (usually on the rudder or somewhere else at the rear of the boat) which "sucks in" the water from the pond/lake/etc when the boat moves forward. There is no pump, just the forward motion of the boat forces water into the pick-up.

The cool water is then directed to the ESC and usually the motor too, then the hot water is expelled back into the pond/lake/etc...

For computer water cooling, there is a 12V DC pump that moves the water around. A radiator cools the hot water down before it is pumped back to the waterblocks (heatsinks).

I'm in the RC hobby AND computer water cooling hobby so this is from my experience.

Can't really see what is going on in the video though. Not practical to water-cool a ESC for e-bike use. Hope this help...