The Stovebolt Site Forums The Shop Area The Electrical Bay O/T: 24V?

Can one of you volt doctors tell me the advantage, if any, of a 24V system on a Jeep? I know the downside, but what does it do better than a 12V system?

24v needs fewer amps to supply a given power .... 24v has less line loss with on same size wire ....24v was/is used on heavy equipment, maybe they did it for jeeps to make'em common with other equip .... the downside [expense and availability] is less since 24v has become common for solar setups

Bill

The military introduced the 24 volt system to have the ability to operate vehicles in adverse weather conditions, and for standardization.
In addition, the add on equipment like radios (especially the early units) require more capacity. For a normal driver, a 12 volt system is fine. Unless you are trying to restore a military vehicle to original configuration there is no advantage. The 24 volt charging system components are expensive to rebuild.
Fred

All I'll be looking to do is maintain a 24V system which is currently in good condition; I've acquired a civilian Mitsubishi Jeep from Japan which, apparently, shares an electrical system with their military version. I was wondering why they overspec'ed their electrics. I once had an ex-Canadian M38A1, a 1967 Kaiser which had a 24V system. I learned that components were not as readily available and more spendy when they were, but were not often required. Bulbs, everything lasted longer. The difference is that the Mits is not set up to be submersible, and I was wondering if there was another reason they left it 24. I reckon you're right, Fred. Standardization is it.

I did a complete restoration of a 51 M-38 about 2 years ago. The owner was able to find all the parts through military suppliers around the country. Fortunately all of the charging system components were good. Parts were expensive but relative to other old cars & trucks, not so bad.
If it works fine, drive it and enjoy it. If at some point the charging system dies, it's not a major deal to convert to a 12 volt alternator, ignition system, etc.
Fred

This is somewhat off the topic, but related. The auto manufacturers were talking about going to a higher voltage system in cars within the next few years, first 24 volt, then 36, and by around 2010-12 going to 48 volts. This was mainly considerd because of all of the extra electricly operated stuff they feel that new cars just have to have. That whole idea has been scrapped for now, as there still isn't an economical 36/48 volt charging system that can be used without significantly raising the cost of manufacture.

You can get 120 volts or more out of an alternator simply by bypassing the voltage regulator, it just depends on at what level you want to regulate the voltage. The limit on the power ( KVA ) rating of the alternator is the size of the wire in the windings. You can increase the voltage, but with the same size of windings in the alternator, you have to proportionately decrease the current to maintain the power rating of the device The advantage of using higher voltages, is that you can run smaller wires and the components are smaller The real problem is, that as the voltage gets higher, the problems of safety become much greater.

So, from all this what I'm getting is that the 24V system is good in an off-road vehicle because situations which are normally to be avoided - such as dirt, water submersion and impacts - have less effect on a vehicle with a higher voltage. That about cover it, do you think?

I think in your case the main advantage to the system that you have would be starting in inclement weather. Otherwise it has no greater advantage for off road use than any other conventional 4X4 with a 12 volt system.
Fred

24 volt in an off road vehicle would also give an advantage if you were running electric accesories, such as a winch or on board welder.