12 Volt Power - Deuce with 3 or 4 batteries

[BlizzardX23]

This is what I have in my battery box...1 battery is not being used (2 arent being used...but only one extra fits in the box)...I want to hook that battery up so that it charges with the system and doesnt slow drain to death. Should I hook that battery up in parallel to one of the others?


I have done the search, and I've read the posts about 12volts in the deuce.


My question to you all follows:

- I'd like to have my 24 volt system stay the way it is...
- I would like to hook up the 2 extra batteries in parallel for the amps to run anything I may wish, on 12 volts.

This is how I picture it...
Somehow, hook my (2) extra batteries up to my (2) truck batteries to charge while I drive...then while camping, disconnect the extra batteries from my truck batteries with a cut-off switch and use those for camping...if the extra batteries die while camping, my 24 volt system is still full and wont leave me stranded...

As well, if Im out off-roading, I can run all my extra 12v lights and tools on my 12v system



Any suggestions or tips?

I've seen the converters/inverters/regulators...but dont know if that would work for what Im asking? plus, those will fry if I go through the shallow part of the lake (water in cab)

 

[cranetruck]

A couple of pointers...

Note 1: Since the additional two batteries will not be used for engine starting, smaller awg wire can be used for switching them in and out of the charging mode.

Note 2: If your 12-volt batteries will be deep cycled when used, don't use starting batteries, they will not recharge fully after only a few deep cycles.

 

[BlizzardX23]

cranetruck, thanks for the input! Note 1 is appreciated!

Note 2 is also appreciated..but I dont understand it, can you explain?

 

[mudguppy]

get a battery equalizer - then you can pull off of the first battery without any other considerations.

that's what i've done. i got a Vanner 100A equalizer off of eGay for $65 - so i can pull up to 100A of 12V and the equalizer will compensate continually. i've added 11 different 12V circuits to my truck. there's actually one more to do.

you'll be time and hassle ahead using an equalizer.

 

[BlizzardX23]

So with this battery equalizer, you say put it on the first battery? As in the left battery? or the battery connected to the generator? then I would hook my 12volt batteries in parallel, then run one of those off my generator battery to charge them?

 

[mudguppy]

no. leave your two batteries connected in series. the equalizer has three connections: 1 to the 12V (1st battery positive), 1 to the 24V (2nd battery positive), and 1 to ground.

you then draw all of your 12V off of the 1st battery positive (i ran one wire from here to a fuse block to pull 12V from there). the equalizer maintains voltage between the 2 batteries, whatever the voltage is; it just makes sure each battery gets half of the total voltage.

your charging system remains stock - generator power wire to that second battery positive (via the starter cable).

 

[BlizzardX23]

Does this look right?


I forgot to illustrate ground cable for 12v batteries to truck...but aside from that...is that how it would hook up?

 

[gimpyrobb]

As a side note, I have seen someone that had hooked up a second battery in parallel to the 12v side and after some time(I think) it caused the alt to catch fire. I don't recommend it.

 

[BlizzardX23]

oh ****

 

[gimpyrobb]

The equalizer or a 12v alt would be the best choices imho. I do know some of our members sell 24-12v converters. I got one from headwizard that can maintain a separate 12v batt.

 

[BlizzardX23]

Do you have pics of your install?


I dont have to have that 2nd 12v battery...just, I got 4 when I replaced my old batteries a couple weeks ago...so I dont want it to go to waste

 

[gimpyrobb]

I don't have pics sorry. Guess I'll have to do that next time I'm at Crusher's.

 

[rlwm211]

I would use an inverter to charge the 12 volt batteries and use a self resetting circuit breaker in line with the inverter's output to the batteries to limit amperage to the 12 volt batteries. Deep cycle batteries do not like high amperage charging and this would serve to limit the initial charging amperage rate.

I would rig the inverter up on a switch that is wired so it can only be turned on with the power switch for the truck turned on. This would allow you to charge the truck's starting batteries if they were low without the extra drain of the invertor and then when you were ready you can turn on the invertor and charge your 12 volt batteries while the truck is running.

By limiting the output amperage, you also limit the input amperage and that way you do not constantly put your truck's alternator under an excessive strain.

I have a couple of inverters and one is from a business aircraft and is a fan cooled 24-12 volt inverter rated for 50 amps 13.5 vdc. I would never use that much as it would be a constant 25 amp plus load on the truck alternator.

Just my two cents

RL

 

[treeguy]

Check out OK Offroad, they have a couple of units that take 24 volts and make 12 volts without the need for another battery if you don't want but I did. Do a search in here for another post that I explained this a little more.

 

[Stalwart]

For an equalizer follow these instructions:

 

[rlwm211]

I understand the principle of the equalizer, and would consider it, except that I use my 12 volt batteries for housekeeping in my shelter and also for communications work. If you run your 24 volt system down too far, you will not be able to start the truck. Further aggravating the situation is that if you use your 12 volts when the 24 volt system is not chargiing, you are running down starting batteries which are not designed to be used in that manner.

I use deep cycle batteries for my long term use and leave the truck batteries for starting the truck.

Just my two cents

RL

 

[DUG]

TM America's 12 volt alt kit is 50 bucks. Any decent auto parts store will sell you an alt for that kit for less than 50 bucks. Even with the one new belt needed you're only just at 100 or slightly over that.

Then your 12 volt side and your 24 volt side don't mix. I went with both his kits and switched my 24 volt alt to a one wire that sells for 123 shipped. Cheap enough to keep a spare under the seat.

 

[rlwm211]

Agreed on the alternator kit for 12 volts DUG. The cost in that venture is the batteries if you are planning on deep cycling them. They do not come cheap.

RL

 

[Dirtygrunt]

Is one of those alt. kit one where you can add a gm one wire and still keep your same 24v alt..

 

[Stalwart]

I understand the principle of the equalizer, and would consider it, except that I use my 12 volt batteries for housekeeping in my shelter and also for communications work. If you run your 24 volt system down too far, you will not be able to start the truck. Further aggravating the situation is that if you use your 12 volts when the 24 volt system is not chargiing, you are running down starting batteries which are not designed to be used in that manner.

I use deep cycle batteries for my long term use and leave the truck batteries for starting the truck.

Just my two cents

RL

That is a concern, but you can put a continious duty relay on the 12V output of the equalizer (three battery config) so that the equalizer is only putting out power to the 12V battery when the ign. sw. is on.