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Slave jump Hybrid 12/24 system

Recovry4x4

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Are you wanting to be able to jump start both 12V and 24V vehicles with a CUCV? Your CUCV should already have a 12/24V system and in it's factory configuration can jump both voltages.
 

dstang97

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Yea I wanted 12v for the winch and jump starting 12v vehicles. And 24 for military. I may take out the black out light and install another one. I wish a boat switch could work.
 
Well if u buy a batteryt with top and side posts u could easily just put the cables from the orginal 24volt to your back battery side posts and the one u put where the black out is on the driverside to the side posts on the front battery thats what i was gonna do hope that helps :]
[thumbzup]
 

pigfoot63

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I made mine plug and play. I have my winch reciever mounted so i can use it front or rear.
I installed a nato plug on the rear bumper and am using froklift type battery connectors on
the front nato plug so I can run my 12 volt winch or 24 volt to juump start, I also have a
reciever mount crane that is 12 volt and can use on both ends.
 

kenklausner

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I have made just what you are looking for for my Pinzguaers. 24 VDC normally connected to the vehicle for operation of the vehicle. the batteries are wired in series through heavy contactors (12vdc coils). at the flick of a switch mounted on the battery drawer the contactors (2) change from a series connection to a parallel connection and disconnect from the vehicle at the same time. I have a 2 pin slave rec. mounted on the vehicle and can provide 24 or 12 vdc out and take 24 or 12 vdc in. There is also a master battery keyed cutoff switch that disconnects the slave cable from the battery pact and is kept on the ignition key ring so the ignition has to be off and removed to be able to operate the master battery cut off switch and prevent pumping in 12 vdc from the slave rec. while the vehicle is running. There is also a digital led voltage meter with a toggle switch to select the battery pact voltage or the voltage at the slave rec while the master battery cut off switch is open to verify the voltages match before the master battery switch is operated. All this is in a nice compact steel tray that can be pulled out of the battery box and automaticly disconnects the vehicle and slave cable connections from the vehicle using two pole anderson connectors.

There are standard parallel-series relays out there for 12 to 24 volt change over for starting purposes but no 24 to 12 volt change over relays, I had to build my own.

it's over kill but convient, it allows me to remove the battery pact simply by pulling the pact out and lifting of the slides, nice in the winter when the truck is going to sit for awhile. unless you hang with a all military crowd and 24 vdc is available the chances of getting a 24 v jump are nill. This set up allows you to jump somebody at 12 v or get jumped or at least get your batteries charged at 12 v. then switch back to the 24 volt mode and start your self. very convient.

I can supply a diagram and a few pictures if desired.

Ken K
 

tcody

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Couldn't you just use a step down transformer with the slave plug on one end and a jumper end on the down side? The current would be higher on the 12v side - not sure what this would do to a battery???
 

kenklausner

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tcody: A tranformer is an AC device and does not work with DC. There are DC:DC converters to change DC voltages which are principaly used in electronic applications were current requirements seldom exceed 25 amps. The current levels and surge requirements for jump starting applications make a DC:DC converter impractical, try and find one in the 200-400 amp capacity with additional surge ability.

The most common mistake made by trying to fulfill the dual 12 and 24 volt voltage requirements is that the 12 volts is usually taken from only one battery, usually the one that has its's neg. connected to the chassie ground, this of course assumes that a person is dealing with a normal 24 volt system with series connected 12 volt batteries. This is problematic when charging takes place from a 24 volt charger as the different states of discharge of the two series connected 12 volt batteries affect the charging voltage developed accross each battery which becomes very unequal. Not certian what the CUCV voltage set up is but if it has dual 12 volt batteries wired in parallel for normal operation then get wired in series for 24 volt operation there has to be a parallel/series change over relay involved somewhere. What's the alternator output, 12 or 24 VDC?

If a person is trying to operate large current 12 volt devices or provide jump start capability at 12 volts, then both batteries should be drawn upon for the application which would necesitate putting both batteries in parallel. For smaller 12 volt load applications from the 24 volt source a 24:12 voltage equalizer can be used. Somebody have a link to the CUCV TM covering the batteries and charging system?

FELLAS! OPERATING 12 EQUIPMENT FROM ONLY ONE BATTERY IN A 24 VOLT SYSTEM WITH 24 VOLT CHARGING IS A NO-NO!!!

warthog: Iam home for the weekend, when I get back to work Monday I'll get the pics and diagram.

Regards, Ken
 

mikew

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I'm preparing to do the same thing with my bobbed deuce.

This is what I'm going to use:

Detailed Specifications for e-Series Battery Switch, Selector 3 Position - PN 11001 - Blue Sea Systems

It's a marine grade battery selector switch. It will let you switch between two battery banks (or 12v and 24v system) but does not allow for both banks in parallel (handy for a starting boost if both banks are the same voltage but very very bad if they are different voltages).

Connect the bank "1" to 24v, bank "2" to 12v and the common to the slave connector.

I do assume you have a battery balancer if you're pulling off the "center tap" of your 24v batteries or a standalone 12v battery.
 
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kenklausner

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MikeW:
that'll do it but aren't you concerned what is going to happpen when you draw heavy current off the one battery while 12 volt jumping? See how the 24 volt charging voltage divides up accross the two batteries after pulling a good load on only one of the batteries, you'll be suprised!!!

Ken
 

mikew

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edmond, ok
Ken,

Yes, you can't just pull a load off the bottom battery (to get 12v) without doing something like a battery equalizer. Over time, and not that much time, you'll overcharge the top battery and fry it!

Other options are a second alternator or a dual voltage alternator feeding a dedicated 12v system/battery.

I'm going to run a battery equalizer thats feed a dedicated 12v battery, 3 batteries total (two for 24v and one for 12v) that way I've got a spare on-board if a battery fails (broken plate, etc.)

And by the way, you don't have to get a battery equalizer that can supply as much current as the peak your load will be using, just more than the average amps.

The switch I mentioned lets me have one slave connector that can be either 12v or 24v.

Here's a link to the attached pdf:
http://www.vanner.com/wp-content/uploads/2010/12/Battery-Equalizer-PB-6-01.pdf
 

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dstang97

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Mike-both CUCV alternators are 100 watts which should be more than enough for both my applications (winch and sometimes for jumping). What do you think?
 

Recovry4x4

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Far and away the easiest and least trouble prone is the second slave plug or a commercial plug like warwag shown. Why complicate it a hundred ways to Sunday? The truck already has the ability to provide current in both voltages without going to an isolator. It's not like a straight 24V vehicle where you have to chop voltage or compensate for a center tap. Everything is there, add a second receptacle or a commercial one, install in 10 minutes and slam the hood.
 

mikew

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Dstang97,

First and foremost, I know nothing about the CUCV! I jumped into this thread because it was the top thread when I logged into steelsoldiers and I am planning on doing the same thing you are doing.

That being said; I looked at the CUCV wiring diagram and Recovery4x4 is correct. The way the dual alternator system works on the CUCV, just like a battery equalizer, you don't to worry about battery imbalance (thus frying batteries by pulling large loads on the 12v side). And setting up a series/parallel switching system is not necessary either.

You could install a second socket, connected between ground and positive on the "bottom" battery, for 12v or do a switch like I am doing so you can select voltages.

In my case I'm putting additional slave sockets on the front and back of the truck, plus the stock one on the passenger side. For me the switch is by far the easiest way to get dual voltages at those sockets.

For you, either an extra 12v socket or a switch would be a great setup!
 
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