I need a 24 volt alternator for a certain project. Searching around on the internet, these alternators seem to be ridiculous in price. Are there any cars/trucks that came stock with 24V, that I might find in a junkyard and get a cheap alternator?

 

The only 24V vehicle I've seen was a '52 GMC M135 6x6 military truck. And it was a generator, not an alternator.

I find several with a simple search, for tractors and other equipment.



https://www.ebay.com/p/15042398547?iid=185239585794

$120+ to over $400.

You want a $10 junkyard one, you might be looking for a while.

 

Its possible some airport equipment might be 24VDC, like tugs etc. If you have a local heavy duty alternator/starter rebuilder they'd be my first call.

 

All the airport vehicles I've seen have been 12V; but I've only worked around small to medium aircraft, not the big jets. I wonder if ambulances ever have 24V...

My intention is to have an emergency backup charging method for an off-grid solar 24V system. This means I need an alt with a respectable amp output (to minimize engine running time), and since it's only for rare use, I can't really justify spending $400+ in addition to mounting and wiring. A bunch of candles would be more cost-effective

 

It would probably help you if you told us exactly what you're trying to accomplish. Back up charging for a solar system makes no sense as solar provides charging.

 

A regular generator would be a better backup. More versatile, probably safer.

Unless you are going to try to turn the alternator using wind.....

Those links and other suggest different types of equipment like Komatsu, Hitachi, Deere, Cat, Case and other ag equipment.

Hours of entertainment possible here:


Short version: If you take off the voltage regulator and spin it hard enough, you can get 25 volts out of a 12V alternator. Some assembly required. Not sure you could spin one 4000 rpm with wind power.....

 

Why are you directing this at me?

 

I double checked on google and it seems that buses and bigger trucks (diesel) use 24 V systems. SInce these are heavy duty commercial vehicles, I wouldn't think that they would be cheap.

Sorry,

hj

 

I quoted you because of your comment "....Back up charging for a solar system makes no sense as solar provides charging."

Which I agree with, and added that if he needs a backup, a regular generator would be a better idea. Because "Back up charging for a solar system makes no sense as solar provides charging.'

So it's a quote, not a criticism.

 

My desire is to mount an alternator to a sled with a pulley and belt and make it connect to a tractor PTO in order to provide charging to the 24V battery bank. Would need about 100 amps to make it worthwhile. A backup charging method would be useful in case of, say, a week straight of heavy overcast (as just one of several scenarios I can think of).

I knew someone would say this! Not that there's anything wrong with that idea, but I personally I don't care for it because (1) portable generators are not really known for being super reliable; I have more faith in the old diesel tractor, (2) both the tractor and my truck are diesel, so it would be an annoyance to store gasoline just for a generator that I hardly ever use, (3) a regular AC generator would require a separate 120VAC to 24VDC high-amp charger, which is a complex and expensive piece of electronics, and (4) the alternator idea would just be more fun to build!

Anyways, if this idea turns out to be too much trouble/expense I just won't bother with it; but it would be fun to do.

 

Sounds like you're trying to justify building the contraption so I say go for it.

Today's inverters/generators are very reliable and dependable and its proven day-after-day almost everywhere AC power is needed but not around.

Good luck!

 

an older leece neville 24 volt semi alternator would fit your requirements nicely. they are pricy though.

 

Probably be cheaper to run twin 12v alts and batts wired in parallel to get 24v.

 

or a parallel switch. charge at 12 volts, but run at 24 like the old Mack diesel trucks did.
but parallel switches are a pain in the butt. when they work, they work great. when they do not work properly, they are a royal pain to figure out and get working properly again.