Community Forums

ckrkrovers · 01-26-2017, 07:55 AM

We would like to replace our two coach batteries for 4 6 volt batteries but they won't fit where the 12 volt ones are now.
Has anyone done this, if so where did you put them? Would like to know if they can go in the bay to the left of the stairs under the fridge. Hoping to add solar later this year and this is the first step.

Thanks
Carol K

BFlinn181 · 01-27-2017, 11:09 AM

Why not just find a place for the 2 additional batteries and keep the present place for the first 2? Putting 4 batteries in a new place is a lot of weight. Have you weighed the RV to see weight distribution as it is now? Changing from 12v to 6v will require new cables anyway, so putting 2 more in a remote location shouldn't be too much more complicated. Just be aware of the out-gassing needs of the new battery location, they can be quite corrosive if not properly vented. Also make sure you use adequate sized cables for resistance over distance.

ckrkrovers · 01-27-2017, 07:15 PM

Once the coach has had all the batteries and panels installed we will weigh to see how much weight we have left for our "stuff", but no we haven't weighed it yet.
I thought we shouldn't mix 12 v and 6v, from what I have read all batteries should be the same but maybe I am interpreting what I am reading incorrectly?

Carol K

JBP · 01-28-2017, 04:53 AM

In my 369 the top step is removable. I think that it is the same in the 378. I think that is where the battery use to be.

wrapperman · 01-28-2017, 03:48 PM

I replaced my 2 12 volt OEM batteries with 2 Trojan 1275. Virtually the same power ratings as 4 6 volt batteries and I didn't have to figure any new space. Fit snuggly in the same location. We have the 2013 378XL. I found both batteries for 318.00 online, no tax and delivered.

2013 Georgetown XL 378

Sent from my iPad using iRV2 - RV Forum

twinboat · 01-28-2017, 06:10 PM

Switching to 2 Trojan 1275 batteries will give you 300 AH, probably 100 AH more then you have, but not as much as 4, 225 AH 6 volt batteries. They will give you 450 AH. Batteries in series double volts, but not AH.

If you have the height, 2, Trojan L16H 6 volt batteries will give you 435 AH.

As far as mixing types, I have 1, 12 volt and 2, 6 volt batteries in service right now. Its been 2 1/2 years and seems fine so far.

Here is a write-up about it from Yandina.com

Q**Can I parallel old and new batteries within one bank?
Q **Can I parallel different size batteries within one bank?

A**Although the conventional recommendations are not to mix old and new, good and bad, big and small, etc. in parallel, those misconceptions actually only relate to batteries in SERIES. You should understand the reasons and make up your own mind. The truth is that you can parallel just about anything. The downside is, if they are not matched, one battery (the newer) will tend to carry more of the load and the total capacity will be slightly less than the sum of the individual capacities. If your new battery has a capacity of 100AH and the old one still had 45AH left, then in parallel you will get something around 145AH, where had they both been new 200AH would fit in the space, but it will help and it will work.

When the old one eventually dies, it will drag the new one down but this happens whenever two batteries are in parallel and one dies, the only difference here is it is going to happen sooner than it would had they both been brand new. So big deal, you gained some residual use out of the old one and the new one will not be permanently damaged - just charge it up again.

The bottom line is the batteries in parallel provide more power - never less - than either one on its own - it just may not be the "ideal" way to do it.

Unplanned Tourist · 01-28-2017, 06:26 PM

I managed to slide 2 220 amp/hr group 31's into where my originals were. (440 vs +- 250 amp/hr) Twice the battery power now. Same location, just had to change hold downs and re-arrange the cables.

They are combination start/deep cycle, so take a charge fairly fast and hold up well for many charge/drain cycles. I have been happy using these types for 10+ years now.

twinboat · 01-28-2017, 06:54 PM

Quote:

Originally Posted by Unplanned

I managed to slide 2 220 amp/hr group 31's into where my originals were. (440 vs +- 250 amp/hr) Twice the battery power now. Same location, just had to change hold downs and re-arrange the cables.

They are combination start/deep cycle, so take a charge fairly fast and hold up well for many charge/drain cycles. I have been happy using these types for 10+ years now.

There are no 220 AH, Gp 31 batteries out there. The best is about 110 AH.

An 8 D battery, about the size of 3, GC2s has about that much capacity.

wrapperman · 01-28-2017, 07:40 PM

Sorry about my typo.

I typed my answer wrong. I should have said 2 12's will give about the same output as 2 6's. About 220 ah. Not much difference.

In my coach there is not enough room to place 4 6 volt batteries. I never needed more than 20 hours of battery power anyway. This is what 2 T1275's have given me with a residential fridge and lights.
If I ever need the extra power either I'll fire up the generator or I'll add solar cells on the roof.

2013 Georgetown XL 378

Sent from my iPad using iRV2 - RV Forum

ckrkrovers · 01-29-2017, 06:02 AM

Thank you all for your comments. Still looking for someone that has moved their batteries though, surely someone in a Georgetown must have?
I suppose its always feasible to get the original battery holder re welded bigger and keep them under the stairs. Would need to make sure it could support the weight.
Hopefully I can find someone who has either moved them or altered their battery holder.

Carol K

gronotte · 01-31-2017, 05:57 PM

Problem is there isn't much room down there unless you fab up another battery tray. Even then it's tight
I just added a third battery to the existing setup
Works just fine
Be sure to identify all your cables so they don't get mixed up or cross wired.
Good luck
If you want a pic let me know and I'll pull ff the step cover and send you one.

Unplanned Tourist · 01-31-2017, 10:19 PM

Quote:

Originally Posted by twinboat

There are no 220 AH, Gp 31 batteries out there. The best is about 110 AH.

An 8 D battery, about the size of 3, GC2s has about that much capacity.

Sorry, I must have been seeing double!

They are 110 a/h each. the old ones were around 1/2 that and a few years old, so degraded I would think. I'm happy with the 31's.

okmunky · 02-12-2017, 09:31 AM

Carol,

The batteries in my FR are also under the steps. When I switched to 6 volt batteries, the compartment lacked a 1/2 inch being tall enough so I had to place a shim around the perimeter of the top edge of the battery box and use longer screws to secure the step.

I was thinking of increasing my solar capacity and would definitely leave 2 batteries and the charge controller under the steps and place another pair of 6 volts in the closest bay. BUT! My bays are plastic bins and I'm not sure they can handle the weight. I'm thinking adding more isn't worth the expense.

Two Costco 6V golf cart batteries and 272 watts of panels handles 90% of our needs. You might start with 2 and see how that works for you before adding more. Good luck!