24volt to 12volt - Page 2 - Steel Soldiers::Military Vehicles Supersite

gimpyrobb · 11-10-2009, 01:24

As stated, the 24v system works just fine. You can get 24v-12v converters like the one Headwizard here on the site sells. You can get a dual voltage alt like in some of the newer trucks. Or there is always the 12v swap. The option that suits youbest, is the best option for you. It costs nothing to keep the 24v system and see how it fits your needs.

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1956_4x4 · 11-10-2009, 11:29

I converted my M1031 to a 12 volt system years ago. I had no real desire to make the conversion, but the starter burnt up on me and a 12 volt gear reduction starter was cheaper/available. Rewiring the batteries to 12 volt doubled the available amperage and helps out since the fire trucks I might jumpstart are always 12 volt.

I would guess that a "fear of the 24 volt system" would not really be an issue, since a person that makes this type conversion should have a basic knowledge of electronics.

I wouldn't convert a system just for the joy of the conversion. If there is a reason to justify the expense/labor fine, but the manufacturers usually put a lot of time/money into the R&D for their vehicles. Sometimes the design might be to ensure compatibility with other vehicles in the fleet (I believe this is the case with the CUCV vehicles...) or it might be for specific product reliability.

I have been happy with my conversion, since it meets my specific needs. It has not given me one problem and keeps running like the proverbial Timex.

Smitty

Snarky · 11-10-2009, 11:42

Theoretically you could use a 12 to 24v converter and charge the 24v batteries using a 12v vehicle, to get enough power to start. Or you could charge each battery individually. Although, that wont help you if you battery goes bad and you just need to fire it up enough to get the engine going and alternators to power the electronic equipment. It's kind of a non-issue on a deuce though, you don't need a jump, you just need a good hill or a push, **** I bet you could get it going to with the correct application of a breaker bar.

glenn · 11-10-2009, 14:41

Quote:

Originally Posted by sangamon

Both my Unimogs and my M656 are 24 volts. I use a little 24V/12V converter for things like my laptop computer, GPS, and stereo.

I needed a jump start once on one of my Unimogs. We just put the 12V jump to one battery for a few minutes, then to the other battery. We removed the cables when starting. We were very careful about grounds and connections, and it worked fine.

As far as cold starting, it doesn't get into single digits very often here in Seattle or Blaine. The coldest I've started is about eight degrees. Instead of starting in one second, the engines took about three seconds. The 24v starter really spins the engine.

Hi Sangamon - Where did you find a 24v to 12v converter and how is it hooked in? I just bought a 5 ton and need to do the same.

Thanks,
Glenn

sangamon · 11-10-2009, 20:10

glenn,

I wire the 24V input to a switched circuit, with a fuse. The 12V output just goes to the stereo and a couple of cigarette lighter sockets.

I got my converters from my Mog guy and a stereo shop. However, they're available all over the internet for $20-$200. Mine are at the lower end because I only run a laptop, GPS, and stereo (which I don't turn up so loud that it uses mass quantities of power).

It's certainly possible to make it more complicated, but that was all I needed.

rmgill · 11-11-2009, 13:12

Glenn, I added a 24-12 volt converter myself in order to power a 12 Volt Brake Controller.

mckeeranger · 11-12-2009, 00:57

If you are looking for 12v power in a 24v system, and you have 2-12v batteries in series, why do you need a power converter?

If you pull power from one battery, that's 12v. If you use the battery that has its - terminal grounded to the chassis/body, you can use the chassis/body for your ground, just like a 12v system.

Even on the 5-ton with 4 batteries. You have 2 batteries parallel in series with 2 batteries in parallel, so that's still 24v or 12v for each of the parallel sets. You can still pull 12v from one battery. (Or in this case 2 in parallel)

Sure, the alternator/generator is 24v, but it's dropping that voltage across 2-12v elements (the batteries), so its power is being cut in half by each.

pjpiche1 · 11-12-2009, 01:16

You can do that. Only if the source that needs power is very low amperage. If you try to pull a large amperage from one battery, you create is a mis match in the amperage between the two batteries in the series. The mis match in the amperage between the two batteries dramatically shortens their life. If you don't mind having battery problems, It is an option.

Jones · 11-12-2009, 01:17

The baby HEMTT is 12 vdc. With the 5.9 Cummins fuel cut-off solenoid, charging and starting systems already 12 vdc it was an easy choice to go to more readily available (and cheaper) bulbs and LEDs.
DATCON gauges match the original HEMTT instrument panel perfectly.
12 vdc for the radio and heater/AC and that's pretty much all I need.
The only 24 vdc system that couldn't be changed over is the one to run the crane, and that's supplied by a "Power Supply, EMCU 116"; 12 vdc in, 24 vdc out.

mudguppy · 11-12-2009, 09:27

that's interesting, Jones, that you went to 12V. since i am planning to do a 5.9 cummins swap, i was on the same fence. but i actually just picked up my spare starter yesterday: i took it to my local starter shop and they rebuilt the cummins starter to 24V. i thought about the fuel shut off solenoid, but those are readily available in 24V also. but my primary plan is to just use a cable like the deuce is set up to avoid solenoid issues and simplify my starting circuit. charging system is the same: 24V alternators readily available to bolt on. i plan to run a converter for 3 guages that still require 12V (tach, EGT, boost).

i just figured, in my plan, it would be easier to change 2 things to 24V rather than 50 things to 12V.

very cool.