hey guys, my question is in regard to running two batterys in my truck. ive looked at all of the trucks at the dealership and got the whole idea, including wiring, spot, and battery looked into. is i know i have to install the other battery in parallel with the existing one. no one at the dealership has ever installed another battery so is that all i need? one mechanic was talking about a heatsink or somthing. but hes not sure. anyone else know if i just hook it up and go?

 

Why do you need 2 batteries? I could see it if you are running a killer sound system, but why 2 batteries?

 

It depends on what you want to do with your second battery. You will not necessarily install them in parallel.

If you want a higher amp-hour rating (for operating the stereo with the engine off), then you could just wire the batteries in parallel and call it a day. However, no two batteries are the same, and the two different batteries could constantly be "competing" with each other, which may wear them out quickly. The solution in this case would be an isolator, which would have one battery just for starting the engine and the other battery for everything else.

The second option would be to use both batteries to start the motor using 24 V instead of 12 V. This is often done in disel engines because of the difficulty in starting them in cold conditions. In this case, you need a very special type of isolator that normally runs the batteries in parallel, but during starting the motor, it places the batteries in series only to the starter motor.

Both of those isolators can probably be found online.

 

How do you plan to keep them both charged with an alternator designed for a sigle battery?

 

I would think you would fry everything if you tried to run the batteries in sereis to get higher voltage.

 

That's why you have to install a special isolator system that is designed for it.

This is one for a Jeep:

http://store.summitracing.com/partde...p;autoview=sku

 

I was just looking at a New F250 with the Turbodiesel. It has two batterys with the positives hooked to each other through a direct wire and both with frame grounds. Seems like having a jumper battery in the truck at all times.

I have been curious about this as well as when I tailgate, we can't run our engines and use generators. I have two Inverters wired into my battery (fused of course, lol) and then a third I can use in the power outlet.

I usually hook up marine batteries to the truck with Jumper cables. I get around 12 vots on the dash, when It drops, I start it for a couple of minutes and use it some more.

I can see how this would hurt an alternator in the long run. Is there a larger alternator we can use? How about if both batteries and dry style and the exact same??

I want to put two optima batteries in the truck. But for now I am not spending a dime in it until I get to the tranny.

 

The newer trucks with diesels are 24v systems, meaning it has one positive hooked to the other's negative and a ground from one going to the frame and a positive from the other battery to the truck. Not parallel.

 

yeah thats why im not running it in series, it would fry the starter, anyway. i have a killer sound system and at an idle it drains the batt sooo bad, even with a capacitor. and im installing a bunch of aux lights to compensate for my headlight covers. i want that battery to run the system and the aux lights. what amp is the stock alt?


edit-- our plow at work is a 93 chev with two batts. its not a diesel and i cant see anything on it other than the two batts hooked up in parralel. which got me thinkin to do it on mine. i cant see an "isolater' of sorts, whats that do exactly? anyway the plow runs fine and never has dead batts or alternator problems. the only thing that went was the tranny. (the owner pplowed with no tranny fluid it in)

 

I don't think you need any kind of isolator for this application. I however would not just stick another battery in there, you need to get a high output alternator to suffice for the other batteries charging needs. Then I would get two optima red tops and you will be set.