9.6 Bigfoot Dual Batteries

The 4D Lifeline was not cheap, but I forget what I paid. 4D size is a standard truck/boat size, but of course not as common as G27, 31, etc. If you can fit 2 more standard (and easier to handle!) batteries I would go that way.

I do not agree with the idea that two 12V batteries is better than one larger one, or two 6V. One cell going bad is quite rare, but still twice as likely with two 12V batteries. Two 6V golf cart batteries wired in series is my preference.

Hi Bcbigfoot! After looking at your profile it does look like your battery compartment on the passenger side is different than mine. My passenger side battery compartment door is below the seam on the clam shell joint. Yours appears to land in the seam and is look bigger. Is it an aftermarket door and cubby?

Wall to Wall inside my compartment is 13 1/4". I will call it 13" and try to fit a couple of AGM's. I wish the 31's would fit!!

I just installed 2 Duracell group 31's AGM's (rebranded Deka's) from a Sam's Club in eastern USA, they were 169$ each (Western USA stocks Eveready batteries). I have a 2005 9.6 2500 series with plastic battery box, must be different than the 2002 Bigfoot's, it's overall width is 13.5" and the group 31's are 31.25" wide.

Before these batteries I had 2x 6 volt golf cart batteries, those were nearly to tall for the battery box.

I noticed that the opening is smaller than the compartment. I will just un-screw the door and put the AGM's in there. Then I will put the door back and re-caulk it. Since they will be AGM's I won't have to service them so no need to take them out. This is all assuming that I am living in a perfect world!

That D4 looks like a beast but would probably serve me well. However, I do like the idea of having more than one battery in case something goes sour.

How much did the D4 cost you? Any equivalents that are not Lifeline Brand(Trojan? They are not cheap but I do understand you get what you pay for.

Not sure if yours is the same, but my 1998 Bigfoot 9.6 could take two G24 batteries, G31 were just a little too big. I put a 4D sized one in there from Lifeline, it is 210 AH so equivalent to two G27 or so. It fit nicely and lasted about 10 years. Only downside was it is a heavy thing to get into the compartment. Terminals are at one end though so easy to hook up.

Batteries will be 8" wide so you should easily be able to fit two Group 31 in your space with its 20" of depth. Some Group 31 AGM deep cycle batteries are 6.625" wide and you might be able to get 3 of them into your space.

A group 31 deep cycle battery is going to weigh between 60 and 70 lbs. so the idea of one big battery is not a good one. With multiple batteries wired in parallel you do not have to worry about one cell taking your "bank" out of commission.

As an example, this site shows the battery dimensions as well as amps.
When you measure the battery box on the camper, measure the opening, not the box, it might have a smaller door .
If you have to, you could always mount a battery in the bed of the truck,in front of the wheel well(s) .
This link shows AGM batts but a deep cycle wet cell can be used with VG results for less money.
http://www.dekabatteries.com/assets/base/1740Intimidatordeepcycle.pdf
I have info, regarding the amount of power that is used by the different appliances in an rv . If you want it, i'll look for it for you.
Depending on your use and needs one battery might work , might not .
I do not let my deep cycle batts fall below 12 volts or approx. 50% of capacity, it can damage or shorten the life of a battery over time . Use a volt meter to monitor the battery as not to deplete it.