Water Cooled Alternators

[Shel_B]

I've watched a few videos in which engines are equipped with water-cooled alternators. These have been on German cars, Mercedes and Audi, and none others that I can recall.

What's the reason for these alternators? They seem overly complicated considering that millions of cars do just fine with just regular alternators. Are these found on cars other than German models? It seems a bit risky to run water and electricity in such close proximity. What safeguards are taken to prevent disaster?

 

[4WD]

2022 Chevrolet Tahoe w/ 9C1 police upfitter package has a 250A alternator.

Air cooled.

https://www.gmupfitter.com/wp-conte...-9C1-Municipal-Specification-Guide-081721.pdf

My Jeep has a 240 amp …

 

[OilMagnate]

For some reason I feel the need to point out this is no different than the air versus liquid PC CPU (or GPU) cooler argument. If anything is going to be sensitive to liquid damage, I'd put PC components near the top of the list. And now that I'm in that world, I can state from experience that liquid cooled is the only way to go.

 

[Shel_B]

200 amp alternators require cooling.

Regular cars, like a Camry, do fine with an air cooled 80 amp alternator.

But high end cars have the additional electric load from four heated seats, heated steering wheels, air conditioned seats, HID lights, and a bunch of other luxury features, in addition to the load your Camry has, and the regular alternator would be unable to provide the needed current.

Liquid cooling is more efficient. 15-20 times as efficient as air cooling.

This has been around for over 20 years. Nothing new.

Thanks. You've answered my questions.

Back in the 1990s I had a couple of F-350 Powerstrokes and was thinking about some modifications. Ford at the time had an ambulance package that included a dual alternator setup. Might that have been a way to get the needed electrical power without the need for liquid cooling?

 

[Astro14]

Thanks. You've answered my questions.

Back in the 1990s I had a couple of F-350 Powerstrokes and was thinking about some modifications. Ford at the time had an ambulance package that included a dual alternator setup. Might that have been a way to get the needed electrical power without the need for liquid cooling?

Absolutely - but the Super Duty chassis of that vintage had a ton of extra room for installation of a bigger alternator.

Air cooled (conventional) alternators work fine, if you have the room.

There is no room in this engine bay. With an inch between the serpentine belt and the cooling fan, a belt change requires removing the cooling fan first. It cannot be done any other way.

A 200 amp air cooled alternator simply wouldn’t fit. The liquid cooled unit is more compact, and it’s under the engine on the passenger side (left as you view this). Also attached to this engine is an AC compressor, air injection pump, and dual power steering/suspension hydraulic pump.

 

[zzyzzx]

I really think alternators need a second winding with a higher voltage output just to run pumps, electric power steering and other high loads that are only need to be on when the engine is running.

 

[2strokeNorthstar]

I replaced a water cooled alternator on a 2000s Cadillac. Pretty simple to R&R. But, I couldn't help but think that my own jeep had more electronic equipment and was served fine by an air cooled 110a alternator.

They were stuffed down where no air would get to it. I always dreaded changing mine when I had a 2000 Deville but it lasted 180k miles, then I sold it

 

[Thermo1223]

Police vehicles have a pretty high electric load. The police Crown Victoria has a 200-amp alternator. It's air cooled. I'd expect that most police vehicles are running air-cooled alternators.

Now think where it's at....it will have no issue getting cooling even in the summer.