24v & 12v questions.

[BKinzey]

My CUC-azer is 12v. I found a 24v winch. I should be able to figure this out myself

I'll be using deep cycle batteries and the question is can I run 12v & 24v off both batteries? Am I wrong in thinking the Military used only one battery for the 12v stuff and two to get 24v?

 

[acetomatoco]

You are right.. The front battery... tap is on negative post of rear battery, supplied all the 12 volt stuff.. The twenty 4 volts were used only for the Glow Plugs and the Starter and a coupla things like the Voltmeter.. Each alternator was 12 volts with a isolated ground and were wired in series to get 24 volts...I would suggest that you use the rear battery for additional 12 Volt accessories and fuse them separately... it is good practice to rotate batteries every year or so... ACE

 

[acetomatoco]

Ok, I forgot the Radio taps from the connector bar by the fuel filter also allow the use of tactical radio sets of 24 volt heritage.. ACE

 

[CCATLETT1984]

you say that its 12v, did you pull the second alternator?

 

[BKinzey]

I pulled just about everything. Going to put in a 6.5 Turbo. Everything would be 12v except the winch. Hmmm sounds complicated now. I think I'm going to pass on the winch.

 

[amanco]

Got a question. When I put a meter on my batteries (two twelve volt hooked up in series) the only place I read 24 volt is on the two posts that my trucks cables are hooked up to. If one end of the meter is on the middle (between the batteries) cable, it reads 12 volts. So why is there so much squabble about 24 to 12 volt converters etc..? Would it be bad to run an accessory off one of the 12 volt batteries? Would it make one weaker and mess up the balance between the two or is there no reason you couldn't come off of a battery with a lead to run a 12 volt accessory? Maybe this has already been answered, I duno? Just trying ot learn here and clear up any confusion in my head.

 

[cranetruck]

If there is a separate charger for each battery, there is no problem at all using one for 12 volt accessories. The problem appears when the two batteries are charged by one charger putting out 28 volts with the batteries still connected in series. If they do not have the same internal resistance (indication of state of charge), they will not be charged properly.

 

[amanco]

That is what I figured. Don't need any problems with batteries so I guess I will stay out of there!

 

[NCINIRATOR]

Here’s a question for the 24 volters; When you are disconnecting your batteries, which cable do you take off first, what could happen if one of the positives touched the body while everything is hooked up?

 

[acetomatoco]

You take off the negative from the front battery... and then the negative from the rear battery cuz the positive from the front battery is also the negative from the rear battery...but you are smart enough to keep any of the cables from touching any metal other than their respective lead posts.. ACE

 

[cranetruck]

The cable that grounds the batteries to the frame comes off first.

After that you don't have to worry about shorting the positive terminal to the frame accidentally with the wrench or whatever tool you are using at the time (the ground terminal can be shorted to the frame at any time without any danger).

When reconnecting the batteries, the ground goes on last.

That's probably what ACE said, but what a heck.

 

[NCINIRATOR]

Thanks. All the time I messed with the batteries I wasnt sure about which wires go on/off first. I always made sure nothing touched anything, especially after I had a nice 4th of July show when I connected the batteries after installing the wrong kind of alternator.

 

[2deuce]

I was considering hooking up a 12 volt winch to the rear of my deuce. Using a quick disconnect between the batterys and the engine not running, just using one battery to power the winch. Then hooking the batterys back together to run the deuce. Never using the winch when the batterys are together. Is there anything wrong with this idea? The battery that was used for the winch would not have the same level of charge as the other after its used but would that matter? Would hooking the batterys back together for awhile equalize the charge between them? Or should I buy a separate 12 volt deep cycle and forget about using the deuce batterys?
Thanks

 

[AJMBLAZER]

I was considering hooking up a 12 volt winch to the rear of my deuce. Using a quick disconnect between the batterys and the engine not running, just using one battery to power the winch. Then hooking the batterys back together to run the deuce. Never using the winch when the batterys are together. Is there anything wrong with this idea? The battery that was used for the winch would not have the same level of charge as the other after its used but would that matter? Would hooking the batterys back together for awhile equalize the charge between them? Or should I buy a separate 12 volt deep cycle and forget about using the deuce batterys?
Thanks

Sounds like you'd drain that battery pretty quick.

 

[2deuce]

I would use it only to pull something on the trailer. I think that would be handled ok by a good battery.

 

[AJMBLAZER]

Ah, thought you were talking about using it as a recovery winch.

 

[jwaller]

If there is a separate charger for each battery, there is no problem at all using one for 12 volt accessories. The problem appears when the two batteries are charged by one charger putting out 28 volts with the batteries still connected in series. If they do not have the same internal resistance (indication of state of charge), they will not be charged properly.

I think it depends on the load you would be running off a single 12V source one 28V dual battery setup.

the 809 250NHC cold start system is 12V and it gets it's feed of a single positive pole of one of the batteries.

I think you could use some smaller amp stuff right off the batteries but for large load 12V stuff you would want to do it differently.

 

[CUCVFAN]

Exactly. The problem is that when you start to re-charge the batteries in series with a 28V alternator, the one that is low will need more current, but they will split the available current. So, the other battery will be getting overcharged while the one used for 12V power is still trying to top off. This is hard on the battery that's not getting used for 12V power...

 

[2deuce]

I thought that if one battery was lower than the other they would equalize the charge between themselves. Is this true? That would be before the engine was started.

 

[BKinzey]

Yes, I think thats true, but that takes awhile. Like days maybe?