truck electrical battery question

[WillieB]

Keep a close eye on specific gravity of both batteries. We want to assure they both stay evenly charged.

[MMW]

Follow up -- I have gotten numerous answers about how to do this & came to the conclusion that it can be done in different ways.

I installed a battery just behind the cab on the drivers side which is right in front of the power unit. I left the original battery under the hood. I ran a heavy gauge cable from the + of the 2nd battery to the battery stud on the starter which tied it into the original battery & charging system. I ran another cable from the 2nd battery + to the power unit. From the - terminal on the 2nd battery I ran a cable to the frame rail & also ran a cable from the power unit to the same stud on the frame rail. It all seems to be working fine & has been in use for a couple weeks now.

Thanks for all the suggestions.

[WickedWrenches]

I am swapping an electric/hydraulic dump rack body from one truck to another. The old truck has dual batteries mounted on the frame rail behind the cab. These run both the truck & the dump body. The new truck (2006 F-350 cab/chassis) has a single battery under the hood. If I mount a second battery on the frame rail behind the cab to run the hydraulics can I just run a second wire from the alternator to the + on the second battery to keep it charged? The + would then go to the hydraulics & the - to ground. One battery for truck & one for dump body.

Adding a second wire from the alternator to charge the other battery is the same as connecting them both together, both positives of the batteries will meet at the alternator connecting the bridge...might as well just connect both batteries together and run one wire to one battery to charge them both. If you just run a smaller alternator wire to the second battery as you stated it may over heat from the draw from pulling current from the other battery. Alternator wires are a lot thinner then battery cables.

[JSFAB]

MMW, I think you are overthinking this. Very unlikely somebody would be running that pump for enough time to drain the battery. Isolators are more commonly used for motor homes, service trucks with hoists, etc. where there may be more battery drain with the vehicle engine shut off.

If you do choose to use a remote battery (close to the pump), I would run the same size wire to it that you would use if you were just running off the original truck battery. Reason being, if either battery goes bad, ALL the power needed for either the truck starter or the hydraulic pump, will be travelling thru that wire. If it is just a 12 gauge wire for charging, it's gonna smoke. I also normally put a 50 amp 12v circuit breaker in, when running heavy wires, if somehow the insulation rubs off somewhere and it shorts out, I don't want it burning up the whole vehicle. Any truck parts dealer should be able to supply you with these circuit breakers. Although not cheap, about $30 - $50 or so, it will help save you from liability if something does go wrong.

Do the job right.

[WillieB]

I've got two tractors each with two batteries in parallel. One had new batteries about ten years ago, no problem. The other had three year old batteries when I noticed there wasn't enough power to crank in winter. One ground clamp was a bit loose, I believe from jostling. Sure enough, it hadn't charged enough, it was dead.
I think you could get many years of good service from two batteries in parallel. It is critically important to keep everything in balance. The problem can be greater in series systems.

[MMW]

I inquired about an isolator & was told that I cannot put one on this truck, 06 F-350 due to the factory charging/electrical system design. I need to get a battery separator. With the separator I'd have to run heavy gauge wire to the second battery anyway so why not just wire two batteries in parallel & be done with it.

All I was trying to do was get away from running 2 gauge wire from the engine compartment to about halfway back on the truck. Even with a separator I would need to do it.

http://www.ase-supply.com/v/vspfiles/downloadables/200tech.pdf

[MMW]

Thought I'd show some pics of this swap. New rear pivot done. The frame extension was already there but only bolted on. I welded it & left the bolts as well. Then cut it as needed before adding the pivots & angle. Basically just copying what was on the old truck.


Hoist riser blocks & boards. Due to the fuel tank location I had clearance issues with it & the hoist. I lowered the tank three inches & raised the body & hoist two inches. I removed the rivets for the cross member & the bolts will go through the hoist, riser blocks & frame. I plan on adding a side plate that will also bolt through an existing hole on the frame.

Separating body & hoist from old truck.


I have not gotten to the electrical yet but have decided to use two batteries with an isolator for the hoist set-up while leaving the original battery under the hood for the truck. So three batteries total. The old light wiring was spaghetti so that will take a little time for me also as electric is not my forte.

[snowbird]

24 volts motors can be run on a 12 volts charging system.

Running a 24 v. motor for a short period can be done on a 12 volts charging system using a parallel switch.

Some heavy equipment had them.

[MMW]

It's 12 volt. Name & model is "Monarch 08111-1 12V". Worked on it some today, mainly focusing on all the brackets etc. so when I pull the hoist & body from the donor it should go right on the Ford. The new battery tray I fabbed is big enough for two batteries. Lots of time spent measuring twice, & then re-measuring just to make sure.

[Bistineau]

Have you determined if it is 12 or 24 volt?

[MMW]

What did you ever find out about this system? Have you started on it yet?

Haven't got that far yet. Just prepping the Ford. Had to lower the fuel tank, add some tabs for the wood to sit on, etc. Something always comes up every time I plan on working on it. Good thing he's not pressing me on it.

[Bistineau]

What did you ever find out about this system? Have you started on it yet?

[walker]

Should run just fine off of one battery. It is not likely to be 24vdc. If you want to add a second, so that you dont have to worry about running down your start battery, just add an isolator.

[WillieB]

Two batteries can lead to balance problems. Whether series IE two 12 volt to give 24, or parallel one can get more charge than the other. It is important to have identical batteries. If parallel, try to keep both with equal resistance, keep all connections clean, tight and coated with Noalox. Still it is helpful once a month to disconnect the ground from one battery at a time and drive 1/2 hour to be sure that battery is at full charge. Then alternate batteries.

[Bistineau]

One thing you need to check is the voltage of the electric hydraulic pump. It may be using two batteries due to the fact it is a 24 volt unit. If so you will need to add another alternator to the truck to get 24 volts to charge the additional battery. Possibly a 24 volt alternator to power the dump independently of the truck's 12 volt charging system.