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Jayls5

Registered
Joined
Jun 29, 2015
Bear with me... this is kind of random.
I've got decent practical electrical knowledge and build my own computers, but never plunged into water cooled setups.

I'm building an electric car:

kaKhgDBm.jpg LyASstdm.jpg

I finally got it driving, but I'm having issues with my motor controller overheating and cutting back power levels to useless output after a little while.

It's a fully potted controller, waterproofed with a single weak factory fan to active air cool the copper heatsink:
yOnBXLLh.jpg .

I'm doing a continuous duty of 20,500 watts to the motor, so I'm probably looking at several hundred watts of heat needing to be pumped out from controller inefficiency. I wanted to do a combination TEC+ liquid cooling blocks mounted directly on the copper. I'll be using a thermal epoxy to secure them.

I have purchased 4 of these cooling blocks:
vnOVtvtm.jpg
Specs: 162mm x 41mm x 12mm. I'm getting conflicting information about the internal/external port diameter. One review stated, "5/16 ID works but could be a little tighter." Another review said, "the barbs are like 3/8". I need help figuring out proper adapters + correct tubing to use on this.

I picked up this for my reservoir:
N2h2FSfm.jpg
Specs: 250mL volume, "Threaded 1/4 G" (Not sure what this is exactly)

I need help with:
1) Selecting a solid reliable pump (or several?) for my multiple cooling blocks. Advice?
2) Any suggestions on good sized peltier (TEC) cooler? I am running a 30AH 14.8v nominal system, peaking at 16.8v full charge. I would prefer not to step it down but can if necessary.
3) tubing, any necessary connectors + adapters. I need reliable fittings, but I don't know what to get.
Do I need a radiator? If so... school me on it please!

I already have any fans and heatsinks necessary for the rest of it. Any help would be greatly appreciated!
 
have you looked at the hybrid cooling systems on the toyotas and hondas?
they are higher coolant flow than we see in computers.
the vibration from a cars going down the road will shake our pieces apart very quickly.
BSP, british, standard pipe thread, can be pretty hard to find here in the us if you are not in a major city.
is the controler mounted in the box on the back? does that box have good airflow throught it?
 
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have you looked at the hybrid cooling systems on the toyotas and hondas?
they are higher coolant flow than we see in computers.
the vibration from a cars going down the road will shake our pieces apart very quickly.
BSP, british, standard pipe thread, can be pretty hard to find here in the us if you are not in a major city.
is the controler mounted in the box on the back? does that box have good airflow throught it?


Yes, everything is in the box. Haven't seen the hybrid cooling setups on the cars either, but I'm working in a pretty small space if that matters.

I have cut holes through both sides of the box to channel air through the cooling path of the motor controller. Extra in-line fans are not yet installed, but I have been just leaving the top open to guarantee the box doesn't heat up until that's completed. I'm not looking for an insane cooling capability with this liquid setup; it's more supplemental to the extra air cooling I'm already upgrading. Those blue cooling blocks were the only ones that seemed close enough in size for my controller, so I bit the bullet even if the ports end up being a pain. Would clamps and universal tubing suffice to connect these components? I'm not going to be off-roading, and it will be a pretty small liquid system. I'm willing to take extra measures (including epoxy) to ensure things don't come apart.
 
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get us some good pictures of the box with the battery and controler installed.
you have been warned, computer stuff will not survive.
to start, hose barbs are a very bad idea for this, you need to use compression fittings.
clear tubing from the hardware store is another bad idea, it has stuff that will leach out and start to clog stuff up.
primochill lrt is what we use.
you need to be using 3/4 inch tube to get the flow rate up but g-1/4 fittings will restrict the flow.
you REALLY need to go and look at the aux cooling systems installed on hybrids.
 
Why don't you take a look at a medium sized copper rad, run a 12v water pump to circulate the coolant a simple 12v rad fan to cool it with electric temp sensor. My only issue with this idea is connecting your blocks to it but I am sure there is a solution to that. Caddiedaddie might be able to shed some light there.
 
While we do watercooling here, I think the operating conditions of a car would push our advice from PCs just outside the realm of being useful.

I would try to contact your local university to see if they have a electric Formula SAE team, they would have built something extremely similar to what you're trying to do.
 
get us some good pictures of the box with the battery and controler installed.
you have been warned, computer stuff will not survive.
to start, hose barbs are a very bad idea for this, you need to use compression fittings.
clear tubing from the hardware store is another bad idea, it has stuff that will leach out and start to clog stuff up.
primochill lrt is what we use.
you need to be using 3/4 inch tube to get the flow rate up but g-1/4 fittings will restrict the flow.
you REALLY need to go and look at the aux cooling systems installed on hybrids.

I will get pictures ASAP, but there's not much to it. The controller design is just a straight path as the picture shows. The stock fan is a small (30-40mm?) acting as a puller on the exit side. I cut holes in the main box goes parallel with the controller's cooling path, and will be adding extra fans and a little duct work before I put the top back on my box (otherwise, it would be recycling warmed air). Basically: Main box inlet -> fan+tube -> controller inlet -> fan+tube leading out back of box. I have 3d printed adapters for these extra inline PC fans.

Thank you for the brand suggestion on the cooling tubes. Will be ordering those! I don't know what search criteria to look up to find these automotive aux systems you're referring to. Could you give me an example to narrow my search terms? Thanks.


While we do watercooling here, I think the operating conditions of a car would push our advice from PCs just outside the realm of being useful.

I would try to contact your local university to see if they have a electric Formula SAE team, they would have built something extremely similar to what you're trying to do.

The local university only has a fairly small scale "autonomous vehicle team", but I don't think they can help all that much. I know the type of stuff they do, and they focus more on small scale builds and programming.

I definitely understand the concerns for vibration/things coming loose though.



Why don't you take a look at a medium sized copper rad, run a 12v water pump to circulate the coolant a simple 12v rad fan to cool it with electric temp sensor. My only issue with this idea is connecting your blocks to it but I am sure there is a solution to that. Caddiedaddie might be able to shed some light there.

Attaching the cooling blocks was going to be the easiest in my eyes. Arctic silver adhesive is pretty strong stuff! I also happen to have some temp sensing relays handy... so I think I'll put those to use. Good call. I guess I could extend the cooling lines out of the box and fit a larger radiator, if you think that would make a big difference. As of right now, I'm severely limited on space.
 
Regardless which path you choose dissipating 700 - 800 watts of heat will require a fairly big rad ....... I would think something in the Mora monster rad or a car radiator of some sort.
 
he's going to need a rad the size of a honda crx along with the fan.

with all the stuff in a 4 sided box with a bottom, air is just sitting there and any flow from forward motion is flowing over the box not into and through.
you have to force air to go where you want it, ducts and fans is the place for you to start.
a great place to start and get an idea of the very basics is a book written by a man i used to know and is gone from us now is engineer to win by carol smith.
if you do any more than change your own oil every shop should have a well worn copy of his full set of books.
 
Most definitely air flow is an issue here. I also agree a big rad is needed and am not sure if a single computer rad even one of the monster rads will be enough. Going the route of using computer water cooling component will in the end cost more with most likely a sub par outcome.

With your background CD I am sure you have a pretty good idea on whats ahead for the OP. I am sure given time and hands on, I could come up with something but that's not possible.
 
where he's going to wind up is proper airflow during forward motion.
when moving, the air in the box has no place to go so it sits in the box and all that useful stuff flowing right over and spilling around.
go throw loose sand in the back of your pickup, close the tailgate and run down the road at 60 mph, the sand will just move to the front of the bed.
put the tailgate down and then the sand will start to move to the rear where it is swept out by the higher energy airflow that is now allowed to enter the bed.
 
NACA ducted intakes, and exhaust tubes exiting in a low pressure area like a wheel well. ;)
 
I would hope that by this point he is on the way to the big box store for some dryer duct to attach to the top roll bar and dump that air into the heatsinks.
 
I would hope that by this point he is on the way to the big box store for some dryer duct to attach to the top roll bar and dump that air into the heatsinks.

I've read everyone's responses, and I'm taking everything in the best I can. I repeated a test drive this morning to refresh my memory about how quickly the thing starts to cut output in its current form. Tomorrow morning, I plan to test with some significant air cooling temporarily rigged up. I have dryer duct, a squirrel cage bilge blower with 4" outlet that has some serious flow, and I'm going to jet it straight through the controller for this test. If I get a raw performance improvement, I can 100% confirm if cooling was the problem.

I'll also remember to snap some pictures this time around.

I went ahead and ordered a few more liquid cooling parts that matched up with what I already ordered. I picked up 2 of this pump + reservoir combo and the

largest radiator that could fit in what little space is left in my box. I know everyone said to get larger, but I want to try seeing if I can keep everything enclosed first. If it doesn't work out, I'll route the cooling lines outside and put in a larger radiator/fan on it. Basically, I have several PC's that I can use this cooling equipment on if it doesn't work out for the car... so no loss. As for securing it, I think I will use automotive screw clamp connectors that are made to hold up to that type of environment.
 
An 80mm Radiator ....... to disapate 700 - 800 watt's, by your supplied /anticipated numbers above you need something like this .........

http://www.performance-pcs.com/new-watercool-mo-ra3-420-pro-black.html

or

http://www.performance-pcs.com/watercool-mo-ra3-360-lt-white.html

or

http://www.performance-pcs.com/new-watercool-mo-ra3-360-lc.html

OR better yet a good AUTO rad and pump. Sorry I am not looking online for these ......

For sure what will not work is some cheap Chinese water cooling parts.

Take for example my FX8370 CPU overclocked to 5GHZ ....... with this OC I need to dissipate about 300watts of heat to do that I need a minimum of 3 X 120 mm rad or 360mm at least 45mm thick.

Good luck with your project.:bang head
 
An 80mm Radiator ....... to disapate 700 - 800 watt's, by your supplied /anticipated numbers above you need something like this .........

http://www.performance-pcs.com/new-watercool-mo-ra3-420-pro-black.html

or

http://www.performance-pcs.com/watercool-mo-ra3-360-lt-white.html

or

http://www.performance-pcs.com/new-watercool-mo-ra3-360-lc.html

OR better yet a good AUTO rad and pump. Sorry I am not looking online for these ......

For sure what will not work is some cheap Chinese water cooling parts.

Take for example my FX8370 CPU overclocked to 5GHZ ....... with this OC I need to dissipate about 300watts of heat to do that I need a minimum of 3 X 120 mm rad or 360mm at least 45mm thick.

Good luck with your project.:bang head



Keep in mind that this controller manufacturer advertises that it requires no external heatsinking. I bought it for that baseline output, not hot-rodding it. I believe the disparity in performance is simply a crap airflow situation. Most people mount this thing in a position that vents heat up and/or has genuinely fresh air exposure. I'm essentially supplementing cooling to meet or exceed those conditions, unless the manufacturer is vastly exaggerating claims. This company is well established and generally regarded as honest though. That being said, I made a sad discovery as I went to test it this morning. The main trans-axle seal is leaking significantly, and that requires motor removal and a bunch of labor. That's a #1 priority at this point.

As promised, airflow path pics were taken:

decIh1pl.jpg

Ignore some stray wires and the white programming cord. I was multi-tasking.
Overhead view of box:
oNEveNQm.jpg

Photos show work in progress with testing going on.
 
If heat is the problem you will need a large rad, pump, and fast fans. Peltier? Thats for ambient as in room temps. There is no way in hell what you need will fit in that box.
 
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