Active Motor Cooling

[Rooster59]

Originally Posted by cgtech

LOL, with our powers combined...... Get a extra bagwell cover, cut holes in it for fans and mount whatever fans you choose in the extra cover. Then the extra cooling doesn't look horribly ghetto, is easily placed right near the heat source, and can easily be reomved when not needed.[emoji106]

That's a great idea. For my gas cart I trimmed the engine cover so there is an 8" gap where it would meet the bagwell to allow heat to escape with help from the fan mounted in the cowl near the shifter. With the electric motor close to the bagwell the fans could be mounted in the bagwell and pointed at the motor. Sounds like it is worth a try. Air outside the bagwell should be cool.

This is the fan I installed. For $30 you would get 240 cfm. Just one exhausts all the heat from a VC625 engine.

GDSTIME 12v 120mm x 38mm High Speed Dc Brushless Cooling Fan https://www.amazon.com/dp/B00N1Y4QOI..._o1GRBbSZA2FAT

[Sergio]

Just another idea, but a bilge inline blower would provide more flexibility in both the mounting and the use of ducts to easily position both air intake and air blower location.

You can get them in different sizes and CFM rating, here is an example:

https://www.amazon.com/Marine-Electr.../dp/B00F7ANK7S

[bronsonj]

I would have jumped at the EMP motor idea a while ago actually, but they don't make one that's sepex. Only series.

The tires may have to happen. $10 each or 4 for $25, rims and tires, used 'decent' stock tires... It'll look goofy, but I will have to make that part of the design... Hmm.

I did remember some CPU coolers I have in the garage. Big copper things with heat pipes. They look a lot like this one except mine are a little larger and all copper:
https://www.dhgate.com/product/lga-2...386943276.html

This is for the Intel Core I-7 CPU and that CPU family runs from 90 to 210 watts IIRC. 2 or 3 of these may be the ticket! If I have 600 watts of heat waste and 3 of these can handle 300 watts of heat (assuming for added inefficiencies of Golf Cart usage vs computer usage)...

I'm thinking of mounting them to the same bolts that ScottyB did for his heat sensor probe. Drill right through the center to make a bolt hole. I need to verify I can do so without hitting a heat pipe, otherwise I need to devise some other method.

[ag4ever]

Originally Posted by bronsonj

I'm thinking of mounting them to the same bolts that ScottyB did for his heat sensor probe. Drill right through the center to make a bolt hole. I need to verify I can do so without hitting a heat pipe, otherwise I need to devise some other method.

Or get some hose clamps from the plumbing store and clamp them on. Might take a few daisy chained together.

That way you could add a bunch all the way around the motor.

I think you will need much larger heat sinks than CPU ones though.

Or wrap a copper pipe around the motor with another coil in a cooler full of salted ice water, and pump cold water around the motor. Just place the cooler in the bag well.

[bronsonj]

Well, we had our 2019 parade last night and I figured I'd really need better cooling as they changed the parade route and made it MUCH longer.

I purchased 4 of these 12v fans:
https://www.bgmicro.com/fan-axial-40...l-bearing.aspx

I wired them in series and mounted them to a thin piece of metal and aimed them at the motor blowing from the top down. I did over-volt them a little but not much. They are 12V rated and at the start of the parade I think I was giving them 14.25 to 14.5v each, no issue.

I connected them to the battery pack with a 7.5amp fuse as my safety and my switch. Then I went almost half the parade route before I remembered I needed to turn them on... But I put the fuse in, fans came to life and I finished the parade. When I got home the motor was hot but not hot enough that you had to let go, I could keep my hand on it even though it was uncomfortable. So that's much better than last year.

Also, I did initially start with wiring the 75 degree centigrade and 95 degree switches, but the 95 degree switch was sounding my buzzer when the motor was cool to the touch... 95C is 203F, so I knew these switches couldn't be trusted and opted to go simple.

[JohnnieB]

Glad to hear you pretty much got the motor heat vs parade speeds conquered.

Next year, start the fans when you start the parade and the motor will be even cooler. That way you'll be dissipating more heat from the onset, so the heat buildup will be slower, which in turn reduces the final motor temperature.

The amp draw will be from about 640mA to 960mA for the four of them, so it shouldn't affect the range much.

BTE: the voltage range for the fans linked to is 4.5V to 13.2V, so you did over-volt the a little.

Here is the spec sheet on the fan linked to.

[bronsonj]

Trying to post pics from my phone...

The first pick is from the ground aimed upwards so you can see the motor and the diagonal array of fans. The second pick is from the lithium battery pack aimed backwards and you can just barely make out the fans above the motor, they are probably 10 inches above the motor with a couple inches of space behind them.

I did set up the 5 amp charger from the generator to the battery pack at the start of the parade. So, yes, I was running a hybrid gas/electric car. But I figure these fans would draw a miniscule current that would be more than offset by the charger and thanks to Johnnie's math I see they do indeed only pull a collective 1 amp.