Battery Location

[RollinMadhse]

I know that using 6V GC batteries is the best choice especially when using solar, but I have 6 12v group 31 batteries that are less than 6 months old so changing them isn't an option. I currently keep two of them in the stock location on the TT tongue, and the other 4 in the bed of my truck and they are wired across when we're parked. If we need to go somewhere I disconnect them and they get an extra charge while we're driving. Far from ideal, but at the time it was my only option.

Now if I'm going to add all this solar I need to have them all together and on the TT all the time but I have no idea where to put them. Has anyone ever tried to put a sliding battery box underneath the trailer? Perhaps in the back between the frame rails?

Once these do die and I replace them with GC batteries I'll be in the same situation so I might as well fix it now.

-mike

[wildtoad]

Won't you have to double the room when you go to 6v batteries?

[jackfish]

No, one would still need six 6-volt batteries in series/parallel to approximate the amp hour rating of six 12-volt batteries in parallel. A sliding battery box is certainly a good possibility. Wherever you put them you will have to be conscious of their weight and the accommodation and distribution of that weight. A Group 31 6-volt battery weighs 70-75 lbs. for 420-450 lbs. for six.

[OLYLEN]

There is no reason that you can't keep your present configuration. Just wire the solar panel and controller to the batteries just like you have your charger now on the trailer. Then connect and disconnect the batteries you in have the back your pick up just like you do now. It won't be the most efficient setup but it will work and not have a lot of extra effort for the moment.


LEN

[Gocoffeer]

I tend to think like LEN....batteries weigh up to 80 pounds each and you just can not build a box and place them in a convenient location on the TT (you would alter the towing capability of the TT) but the solar array if properly designed will certainly charge the batteries in the truck bed too. If you design your system well you might locate the controller/charger in the truck be to be closer to the bulk of the batteries.

[vsheetz]

Originally Posted by OLYLEN

There is no reason that you can't keep your present configuration. Just wire the solar panel and controller to the batteries just like you have your charger now on the trailer. Then connect and disconnect the batteries you in have the back your pick up just like you do now. It won't be the most efficient setup but it will work and not have a lot of extra effort for the moment.

LEN

Agree that the batteries not collocated is not a real bad thing. I have two pairs of 6v, one pair on each side of the coach. 15 feet of 1/0 connecting the pairs. Voltage sensing for charging is not optimal but works ok. I charge with Morningstar TS60a controller and 600w of solar panels.

[Reed Cundiff]

The Open Range 337RLS 5th wheel we have has a storage area at the front that is designed to hold Onans up to the 5.7 kW version. I contracted OR about weight capacity of this storage area and they said that obviously up to 300# and that 400# is possible. So our son installed the LFP (9.7 kW-hours but they weigh only 160#), inverter, controllers etc up there. Others on the Open Range Forum have installed six up to 100 amp-hour batteries in the same area. We looked at a couple of Montanas (really liked them but Elaine liked the 337RLS floor design and we got the same exact model) and they have a huge "basement" area in which one heck of a lot of batteries could be installed. TTs usually are set for 2 x 100 amp-hours batteries but a battery box could be fabricated that could hold 4 x 100 amp-hour 12 V batteries. We had a cheap but nice Maxi-Lite for a start. Relocated the propane bottles slight, put on 2 x 100 amp-hours batteries and there was room for a 4.5 kW Champion generator (really cheap and not that nice but it worked and I liked it -it did require adjusting to keep the correct voltage) on the tongue as well. We moved to 4 x 110 amp-hour glass mats and son Cary installed them in the rather crowded "basement", the "large" baggage compartment along with the 2.5 kW PSW . The took up a lot of baggage space. You have to be inventive on where to emplace them - and use proper gauge wire to avoid voltage loss.
reed and elaine cundiff

[Reed Cundiff]

Should have put this photo in our above post. Another guy at Open Range forum has placed six standard batteries in the same compartment. The front compartment is rated for 300# although OR rep said maybe 400#. I should prefer not to have all those batteries falling through onto the road.

There was room for another two LFP batteries but doubt we need 1080 amp-hours at 12.5 V (860 usable) or, equivalently 13,000 W-hours)

[Paul R. Haller]

I have a large 5er that needed more battery space but I wanted my batteries in their own unsealed compartment. I ended up welding together a large battery box that holds 4 6 volt golf cart batteries made from 22 feet of 1&1/2 x 1/4 angle iron that slid right between the frame rails. It's perfect for what it does and all my batteries are accessible through the storage compartment and open to outside air for venting while not taking up valuable storage space. In my 5er there are just 2 pieces of carpeted exterior plywood that covers that space on both sides of the inside of the storage box. Lift those up and there is 12x60 inches of unused space beneath. I ended up building 2 boxes one is unused now but I can now carry 10 batteries if needed. I already upgraded to G rated tires and axles to 2 8000lbs.
-Paul R. Haller-

[Reed Cundiff]

Paul R. Haller - This is what our son Cary originally thought of doing but then figured that since we did not plan to use the space designed to carry a 5.6 kW Onan, why not use it. There was plenty of space for all the peripherals to the system (controllers, inverters whatal)

Could you post photos of your battery compartment. I know that a lot of folks do not have space.

Reed and elaine