Winch Install - 2011 Ram 2500 Diesel 4x4 - Which Battery to Hook Up To??????

[High_Country]

I have a 2011 Ram 2500 CCSB 4x4 diesel which of course has TWO batteries from the factory. I'm installing a winch (and a large power inverter) :wings: and so I'll be permanently installing some large heavy gauge cable to the battery. My question is - which battery? The driver's side or passenger side? I've heard some say that the truck's computer and other components are hooked to the DRIVER's side and the starter is hooked to the PASSENGER's side. This would make me think the passenger's side would be better - don't want to be messin' with the computer at all.

Does anyone know?

Secondly, does anyone know if the newer diesels come equipped from the factory with a battery isolator? And if not, is there harm to installing one in a diesel?

Thanks!

 

[notajeep]

As far as I'm aware, there is no isolation between the 2 batteries in your Dodge. It be nice to think that the second battery was added to your truck as part of the "expo" package. But the real reason most newer diesels have 2 batteries is because of the very high compression of the motor and the resultant work and amp draw required by the starter. For this reason I would think that adding an isolator to your truck between the 2 factory batteries would be a BAD idea.

Either battery should work fine to attach your winch and/or inverter.

Cheers
Dan

 

[Spencinator]

I believe everything should be hooked to the main battery, which on my 98 is the drivers side battery. The second battery is mainly there for starting. Installing an isolator should be fine as most trucks with campers and RV trailers usually have an isolater installed for the accessory battery in those. It wouldnt hurt to call Warn to ask about the winch install and call the dealer about the battery isolator install. Also a good rule to know is when you need to replace the batteries in your truck dont just replace one. Replace both and have both be the exact same. I have experienced and heard of problems running two different brands or capacities of batteries. Hope this helps you out. This is what I have experienced on my 98 so I would consult warn and the dealer as they will know for 2011s.

Edit: Dont install a isolator between the factory batteries. Not sure if you meant that...

 

[verdesardog]

Your batteries are connected in parallel. It doesn't make any difference which one you hook your winch to, there is no isolation between them. They essentally both work together to make one large battery.

 

[High_Country]

I appreciate all the comments guys. It seems everyone agrees there is no isolation and that the batteries are constantly hooked together. And, if that's the case, as verdesardog said, it won't make a difference so I should probably just pick the easiest battery to hook up to (which will probably be the passenger side because it's the 'cleanest').

I do appreciate the insight and knowledge.

 

[BroncoAZ]

On my 06 Diesel I used the driver's side battery for the 1/0 cables going to the rear of the truck, and the passenger side battery for the 1/0 cables to the front winch. I was looking at upgrading the cables from the alternator and the link between the two batteries to 1/0 as well, but I'm not sure it is necessary.

 

[4x4junkie]

What I would do is hook the positive winch cable to the + on one battery, the negative to the - on the other (ONLY do this if the batts are in direct-parallel hookup). This will encourage equal power delivery from both batteries, otherwise you might have the winch drawing down harder on the battery it's connected to due to the resistance in the cables going to the other battery.

I have dual batteries wired direct-parallel in my rigs and have my winch wired as above.

 

[High_Country]

Okay, here's another question: Just about everyone recommends hooking the negative cable back to the battery rather than going to ground on the frame or something. Why is that? I suppose perhaps some people don't get good grounds when going to the frame and end up having issues but if I grind off the paint / coating, put some dielectric grease on it, and get a real good ground, why isn't this just as good? The negative terminal of the battery is connected to the frame (or the engine) for ground, so why can't I?

By the way, if I CAN go to the frame, since I will be running cables to both the front and rear of TWO trucks (for a mobile winch), this will save me about 50 feet of cable!

So, is it a bad idea, just not normally done, or okay if done right?

 

[4x4junkie]

Because you're then relying on the vehicle's ground wiring which may not be up to the task of handling a winch's current draw (the starter motor's ground is through the engine block, not the frame. The frame's ground back to the battery is often a #10 wire or even smaller, depending on the vehicle).


If you really want to use the frame as a winch ground, you'll have to run some bigger ground cabling from the battery to the frame to handle the current demand. You'll also need some #16 ga. or so copper sheet with several bolts through it to distribute the current into the frame at your connection point as well (a single-point connection into low-conductivity steel is liable to overheat with 300-400A going through it).

If you're not familiar with everything needed to do this correctly, it's probably better to just play it safe and run a separate ground cable from the winch back to your battery.

 

[High_Country]

Thanks for the info, 4x4Junkie. I understand and it makes sense. I didn't think about the smaller gauge ground wire from the battery to the frame - that makes sense. I'll look into upgrading that if I want to go that way. I also appreciate the comment about one ground point connection not having enough ampacity to carry the load.

Time to do some head scratching....

 

[TRACTION]

My winch is connected to the passenger side battery primarily because it was easier to route and cleaner to attach in my 07. I was wondering the same thing as your original post though so now I know.

Just for reference I've run without a second battery in an emergency situation. Had a battery melt down and my rig started fine with just one but it was in warm weather so easy cranking.

 

[gsanders]

Here is the wiring diagram for my 2001 just for reference (and for any future people who might have the same question). It shows the batteries wired together in parallel and then all wiring running off of the two connected batteries.