Battery box for 3 - 12v batteries ?

[Dave Storey]

Im new at this , My wife and I own a 1977 4500 series trillium trailer with no washroom only a porta pottie .
I am in the process of installing a 130 watt solar panel 5ft x 27 inches with existing 15 watt 3 ft x 1 foot on the roof . I have a controller that will handle up to 100 - 12v volt batteries . I am going to use 3 - 12 volt deep cycle batteries . With all this power I should be good by the ocean for weeks in Nova Scotia on our lot . We have access to drinking water near by .

The question : I have to build a battery box to hold three -12v batteries and install it somewhere on the trailer . I will be installing another propane tank at the front of trailer to make it 2 tanks instead of one . Have any ideas to be safe ? Thankyou

PS Just wandering if I should put batteries at the back of the trailer or up by the propane tanks or inside somewhere with a vent . don't want to break the frame if too heavy . I have a sway bar in case the weight of the trailer is off at the front or back while traveling 60mpg or so down a big hill on the hwy .

Dave

[Casita Greg]

As a general rule, you would want to concentrate heavy loads as low as possible, and as near to the axle as possible, within the parameters of the space you have to work with. Locating heavy items at the far front or rear would probably not be the best places.

[Larry C Hanson]

Hello,
Here is some interesting reading that may affect your decision to use 12V
batteries in parallel instead of 6V batteries in series:

Parallel or Serial for your Battery Bank?
Deep Cycle Battery FAQ
Solar Power 101: Batteries part 2 by Jeffrey Yago, P.E., CEM Issue #88

Good luck with your project. Larry H

[Raya]

The only thing with 6 volt batteries (and I'm a fan of them) is that three would not work. You'd need an even number. If you can fit four..... great. Otherwise two. They are a bit taller than typical 12-volt batts, so keep that in mind if you are checking into space for them.

Raya

[Ed Harris]

Does the Trill have the original water tank/bag?
If not then the space under the floor in the dinette area seems a natural spot to me.
If you will keep the dinette as a bed then you could easily build a box that raises the floor some and if not you could build down.
Either way the batteries would be over or close to the axle for best ride/handling.

You could also try for the tongue area but as has been mentioned you don't want too much up there.

Ed

[Dave Storey]

Our Trillium has a water tank under the floor and 12v water pump .
I will be hooking batteries up negative to negative and positive to positive to keep 12v just more amps .
I guess I could put a box under the bed with a vent going outside but rather keep it outside in case of hydrogen fumes from charging batteries leaks inside trailer .
Maybe I will make a box to fit on the front of trailer to fit 2 batteries instead of three

[Casita Greg]

One thing to keep in mind if you are paralleling your batteries from one charger. The charger will charge to the take-up rate of the most discharged battery, thus overcharging the battery which is not as low. You may get away with this for a while, but eventually you will ruin one, if not both, batteries. I would suggest that if you want to install two batteries, to install an isolation switch so that only one would be on at a time. Same for charging.

[Dave Storey]

I was told by a solar panel specialist where I bought the 130 watt panel from ,to use three - 12 v batteries parallel and then hook up the middle battery from the solar panel charge controller ,so charge will be equal out from the middle . Maybe I should build a box to hold three batteries and have it at the front of the trailer and leave the one middle battery in the box secured while traveling and secure the other two in the trunk of the car until we set up for camp at our lot and then install them back in box.
Think that will work ? It may be a pain to hook them back up but it would only take 10 min prob .
At least when we travel the one battery would be good enough until we get to NS from Ontario . Plus the frame and tongue of the trailer wont be stressed out during travel.

[Roy in TO]

A couple of thoughts Dave.
If you check out the specs on various batteries available today you will find that there are usually more Amp Hours on the 6V than there are on the 12V deep cycle batteries. I think you will find that 2 x 6V will approximate your intended 3 x 12V. Many of the 6V I looked at were in the 100-120 range because they are designed for this, while the 12V seemed to be in the 80 Amp Hour Range. Unless you get into the large non standard sizes.

Sway bars and weight distribution are different beasts.

Have you considered ways of limiting the power you need like switching to LED lighting?

My experience on hills in NS is that everybody seemed to slow down below 60 MPH going downhill and sped back up going uphill. Thus negating any effects gravity and momentum would have on the MPG I was able to acheive. Not to mention severely stressing out this driver and his tow vehicle.

[Ed Harris]

Here is the box I put on the front of my 4500.
Thje idea was to enclose the tank and batteries and have some extra room too.
I presume you know about the Trill' weak frame issues right where the frame bends to go under the trailer?
Mine was reinforced with big steel gusset plates but I still would think twice before loading an extreme amount of weight there.

The thing with three batteries just sounds wrong to me.
You want the batteries to all be identicle if possible so they take a charge and discharge together but even batteries that are the same are not truly the same.
Using 2 6volt batteries to make 12v makes the most sense if you can afford the weight and there are connectors that will allow you to have it wired and just unplugged when needed.
They use them for Tow Truck Jumper cables.etc.
Anderson Power Pole is the generic style of those huge connectors.

[Larry C Hanson]

Hi Dave,
I think you need a new 'solar expert.' Hooking up the controller to the 'middle' battery is not a solution as the electrons being
moved do not 'know' which one is the middle one.... they are all the same when in parallel.

On my Trillium I wanted to put two 6V batteries on the tongue.I even bought the batteries and a large battery box to hold them.
(2 x Trojan T-145 Plus's connected in series = 12VDC @ 260 Amp Hours). Trojan Battery Company
The whole setup weighed about 150 lbs and I decided that was more weight on the tongue than I wanted. Those batteries were
installed in my large 5th wheel trailer. A Trojan 130AH RV Deep Cycle was purchased for the Trillium. Trojan Battery Company
Dry camping for a week in it is no problem... I only run led lights except for modified reading lamps which draw only 7 W using
a Malibu yard light halogen bulb. http://www.fiberglassrv.com/forums/f...vdc-38613.html An XM radio setup supplies entertainment drawing only about 5W.

Of course, if you are running computers and/or TV-DVD players you will need much more juice.

Have fun on your project. Larry H

[Dave Storey]

Thank you for all the input I appreciate everyone's help I think I will go to 2 - 6 volt batteries as they seem to hold more amps .
I already have a 12v deep cycle Canadian tire 75amp battery which has been on the front of the trailer all along in a 3/4" wooden plywood box bolted down .The battery is now in the basement for the winter . .
I will build a box to fit the 2 - 6 volt batteries and the 12v battery with a dual switch that will fit on the front of trailer , but will put the batteries in trunk of car as we travel and secure them down in trunk for they wont move in case of a quick stop . Will take them out and put them in the box when we set up for camp.
( 2000 Buick Century) good old clunker Oshawa built .

[Scott H]

Dave,
I have a 4500 with a 130w solar panel, and 2 6v batteries. Here's a link to the thread showing how mine is set up.
http://www.fiberglassrv.com/forums/f...all-42854.html

[Dave Storey]

Originally Posted by Scott H

Dave,
I have a 4500 with a 130w solar panel, and 2 6v batteries. Here's a link to the thread showing how mine is set up.
http://www.fiberglassrv.com/forums/f...all-42854.html

Hi Scott

I like your set up I will prob do the same . I will have a propane tank on the front too though as we have a 3way fridge that uses propane and the odd time we use the propane furnace as it gets cool at night in NS .

We do have a 12v water pump in our trailer it uses little power when used . We use a 13" LCD tv in the evening for 2 hrs and lap top half hr per day . and we are planning to use a 12v 31 litre cooler 24hr a day at 45watts
switching to led lights is good idea . We have 2 small 12v fluorescent lights .

I already have a 15watt solar panel on the trailer . Will be adding the 130Watt in the spring 2011 which is in my art studio against the wall .

Winter is coming here it is near 32 f here burr

They have a government program here in Ontario to have solar panels installed on our house we get a big rebate to go green


Dave

[Roy in TO]

Originally Posted by Dave Storey

we are planning to use a 12v 31 litre cooler 24hr a day at 45watts

Dave,
Since this appears to be your biggest power hog, have you considered a 40L 3way cooler that will run off propane when stopped?