Wiring Batteries

[rodymartin]

OK I know that the batteries are wired in series but has anyone tried a series parallel switch out of a big truck in a cucv?

 

[cranetruck]

If you consider the alternators and that one battery is "floating" and the starter current drain, any 250 amp and up switching arrangement should work.
What's your reason(s)?

 

[doghead]

How do you propose to use such a switch? For what purpose?

In stock form the CUCV has both 12v and 24v circuits. It has 2 batteries that have separate alternators. It's a nearly perfect design.

 

[rodymartin]

How do you propose to use such a switch? For what purpose?

In stock form the CUCV has both 12v and 24v circuits. It has 2 batteries that have separate alternators. It's a nearly perfect design.

Reason is this truck going to be a radio truck. The radios I use are all 12 volt. Also puting a yellow warning light on top. Probably a inverter also.

 

[doghead]

So, how do you propose to wire this? I am not seeing how this would benefit(or even work).

If you want 12v. you can use the front battery and you have 100amp charging it.

 

[rodymartin]

In the 80's I used to work on heavy equipment. Most of it was old and had Series Parallel switches. Start of 24 run on 12. It worked well when you had charged batteries. 24 volts gives you more starting power with less current. That being with less heat and smaller wire can be used. I have worked on prototye vehicle that are 48 volt. the wire is very small.

 

[fasttruck]

A series-parallel switch ? Really? Back in my B model Mack days most of them had a series parallel switch for the sfarter. These were also the beginning of my drinking problem in that they are also part of the charging system and the truck will not start if each pair of batteries (There were two pair of six volt batteries) was not equal to the other. Thank god for 12 volt starters and the elimination of that headache 1

 

[rodymartin]

A series-parallel switch ? Really? Back in my B model Mack days most of them had a series parallel switch for the sfarter. These were also the beginning of my drinking problem in that they are also part of the charging system and the truck will not start if each pair of batteries (There were two pair of six volt batteries) was not equal to the other. Thank god for 12 volt starters and the elimination of that headache 1

Funny thing is that I know where an old B model is sitting right now. The series parallel in the trucks I worked on worked great.

 

[mistaken1]

The military radios used 24V and so they drew off both batteries equally (in theory).

I could see how using both batteries in parallel for 12V radios would allow the civilian radios to draw off both batteries equally (in theory). Plus it would provide more radio operation time before having to run the engine to recharge.

Would it be easier to just add a 2nd (or more) sealed, deep cycle battery paralleled with the front battery and a battery cutoff switch to allow the radios to use this 2nd battery without drawing down your starting batteries?

 

[rodymartin]

If I can keep the 2nd Alternator and put a deep cycle charged by it only for the radios. I have at times had to work with search and rescue here in the mountains. The vehicle will be joined by a M1008 for hauling later.

 

[mistaken1]

In stock form the second alternator floats 12V above the chassis ground.

You would have to convert the truck to 12V only using the driver's side alternator and then modify the passenger side alternator system to have the passenger alternator grounded to the chassis as well.

Do you have the 24v buses in the passenger compartment under the radio tray? What about a 24v to 12V converter to power the radios?

http://www.steelsoldiers.com/cucv/62703-radio-set-up-m1009.html

http://www.steelsoldiers.com/cucv/51076-amateur-radio-m1009.html

 

[rodymartin]

If I could find military radios to cover all the frequencies I need I would stay 24 volt. But they cost more than a new radio. But if I have to it is change everything to 12v with a new starter and glow plugs.

 

[mistaken1]

The truck is all 12V except for the starter and glow plug system. You can leave it stock and wire your 12V radios to the front battery and just ignore the back battery (or rotate them periodically).

 

[skysix]

Major Battery Mods...

My plan - will use AGM batteries as better in cold /don't freeze since no arctic kit to heat them when not plugged in or running.

Battery tray modified with a bolt on adapter to hold 2x Odyssey group 31's. A pair of 6V Optimas fit between trays as single long item on a custom tray (yet to be built) hung off mounts of exiting trays. Solenoids will fit on a mounting plate between the rear battery and the inner fender.

Allows 24v starting, conversion to 12v when parked (for a camper), and self boost in case batteries get too low. Will have auto cutouts so when in 12v mode they are not drawn below 80% (10.5V)

Mockup pics of setup below (can also use 4x grp 31 (Commercial Equip Batteries - Light Truck/Van Mega-Tron - 950 CCA) and a single 3EH 6volt battery (Agriculture Vehicle Batteries - Light Truck/Van Mega-Tron - 875 CCA) a shown.

 

[skysix]

Let try the pics again...

 

[idM1028]

If I can keep the 2nd Alternator and put a deep cycle charged by it only for the radios. I have at times had to work with search and rescue here in the mountains. The vehicle will be joined by a M1008 for hauling later.

Here comes the crazy "let's switch the truck over to 12V" guy! Roscommon 12V conversion. Google CUCV 12V conversion. Supposedly, this is what the Forest Service does to their trucks. There's two ways to do it, both of which you get instructions for. 1. You convert the truck to 12V, and keep GEN2 (which no longer needs to be an isolated ground alt, but can be) yank GEN1 and the wiring, and keep the two batteries (which are now in parallel) or 2. Keep both alts (neither of which needs to be an isolated ground, but can be), GEN2 charges the batteries (again, which are now in parallel) GEN1 charges a completely isolated 12V battery which can be used to power auxiliary equipment (for the forest service: pumps, winches, etc. for you: radios) Very minor rewiring and modification either way.

 

[MakersTeleMark]

I use a automatic charging relay to charge my camper battery off of the front post of the rear battery in my truck. Works very well. It also lets my solar panel charge the truck batteries once full voltage is met on the optima. Simple solution. I can also combine the battery banks for emergency starts should I need to.

Google Blue Sea Add a Battery. Adding a 3rd battery is a lot simpler and wiser than converting to 12v IMHO.