Battery rearrangement

[ramsaymike]

We have a 2007 Coachmen Concord with the Ford 6.0l diesel motor. The 2 house batteries are located under the entry step which I understand is normal practice. The 2 starting batteries are located in a compartment at the back of the motorhome. This seems backwards to me but that is the way it is wired. I assume this was because there was no other place to put the starting batteries. I would like to switch this around. It appears that I can just rearrange the cables at the battery 'combiner' solenoid. Has anyone tried this? Thoughts?
Thanks.

[DrewE]

My class C batteries under the step are even better vented; they just sit on an open tray that hangs underneath the floor. Often when I do maintenance on them I rather wish they were not quite so thoroughly well vented as they tend to collect road grit and other dirt.

[rlw999]

MNRon wrote:
Are the house batteries AGM and the starting batteries regular flooded lead-acid? Remember that regular batteries need to be vented. I'm not familiar with class C's but it could be that the batteries in the back are vented to outside air, while the batteries under the steps are AGM so they don't require outside venting. Just a thought.

My Class-C understep batteries are standard lead-acid, and there's a vent in the back of the battery box. There's a rubber gasket around the step to seal it off from the coach. Since most RV's still come with flooded lead acid unless you pay for an upgrade, I'd be surprised if there's no vent in both of his battery boxes.

[MNRon]

Are the house batteries AGM and the starting batteries regular flooded lead-acid? Remember that regular batteries need to be vented. I'm not familiar with class C's but it could be that the batteries in the back are vented to outside air, while the batteries under the steps are AGM so they don't require outside venting. Just a thought.

[pianotuna]

ramsaymike wrote:

I would need to switch the batteries so that the deep cycle ones are in the new location. The starting batteries may not fit in the step battery box so it may not work.....

If you want more house battery capacity, simply add a 2nd bank with switches.

[DrewE]

Ford's vans with that engine had a (presumably similar--maybe even the exact same) double frame-mounted battery trays, rather than the underhood battery as for gas engines. I'd guess that Coachmen probably just more or less copied Ford's arrangement; my guess is that the great majority of their motorhomes in that era were built on gasoline versions of the chassis, and it made little sense to expend any significant engineering work on the chassis battery mounting for the few diesel units sold.

I modified the battery tray under the steps of my class C to have a bit more vertical height, sufficient to put a pair of GC2 batteries in. It basically involved cutting out the original angle iron at the bottom of the rack and replacing it with one having a taller/longer web on one of the angles, as well as trimming some bits above. It was a bit of work, but in my opinion well worth the effort.

[ramsaymike]

The only reason to consider it is so that I have more options on the house battery side. The battery box under the step it very tight while the rear compartment is much larger. I'll probably just leave it alone and see how it all works out - we have only had it a short time. And as to the engineers have a good reason - I doubt that very much.....I believe this is only for the diesel as it requires 2 batteries and there is no place to put them under the hood. I suspect they did not make enough of them to really spend a lot on design.

[Horsedoc]

Why? there will still be two batteries in the same two places. I expect the engineers and designers had a good reason to put it together like they did

[DrewE]

Where is the wire that goes from the starting batteries to the engine? If it doesn't also connect at the solenoid, you won't be able to switch them around simply by rearranging connections at or near the solenoid. You need the connection from the starting batteries (wherever they are) to the engine systems on one side of the solenoid, and the connection from the house batteries to the house systems--which often for Coachmen RVs seems to be via a little bus bar with a few self-resetting circuit breakers attached to it--on the other side. There should be some sort of overall overcurrent protection close to each of the batteries to help prevent a fire in case the cable from the battery to the systems should chafe and short out or some similar catastrophe occur.

Frankly, if the existing setup is working fine (the engine starts reliably, etc.), I don't see any real reason to change things around, even if it logically seems theoretically when differently arranged.

[ramsaymike]

All cables attaching to the solenoid appear to be the same gauge. There is a fuse. It just looks easy to do as all wires are accessable under the step beside the house batteries, There are 2 cables coming in - one from each battery set - so it would be easy to switch around.
I would need to switch the batteries so that the deep cycle ones are in the new location. The starting batteries may not fit in the step battery box so it may not work.....

[DrewE]

Are the wire sizes and main fuses (near the respective batteries) of comparable sizes?

I'm assuming there is a main fuse or fusible link for the starting battery somewhere near the battery; if not, I think there really ought to be. It could be incorporated into the battery terminal connection(s) or otherwise not immediately obvious.