Battery recommendation? Whatcha running?

[68camaro]

Thanks Blue, I didn't think of weight as an issue but these batteries are 70# each so 280# could be stretch and I certainly don't want to take it to the limit.

I think even with two 6V AGM batteries at 220ah, I can meet my 117ah 3 day usage estimate at a 53% DOD, even at my top end for 3 day usage 72% DOD, based on manufacturer DOD vs. Life Cycle Chart I should be able to get plenty of years from batteries assuming 12 - 18 life cycles per year. This also assumes no recharge from solar, generator or alternator and correct recharging at end of trip.

http://resources.fullriverbattery.com/_ ... vs-dod.png

[Blue~Go]

I agree. And look at it this way: You are not going to be in Outer Mongolia. You can buy new batteries at any time. By only buying two now, you are carrying half the weight, and the money for the next two is "free" (since you didn't buy four now). Plus you will know more about your usage then (at next purchase), and maybe can refine what you are doing. And if you mess up and wreck them, you only wrecked two!

I might still go for two GPL31XT (12 volt AGM, 250ah total, 148# total), but that's because I don't see any big advantage to 6 volt batteries in AGM. Or if you want to stick with Full River, you could go with two Full River Full River DC115-12B. These are 115ah each, so two would be 230ah and 145#. These are what I had in my other project (the DC115-2B). Sure, you save one 12" jumper with a pair of six volts; but on the other hand if one battery dies for some reason (bad cell or something) you have nothing (one six volt battery won't do anything for you). With 12 volt you still have at least one battery. Could save a weekend trip.

(With the old flooded golf cart batteries, the 6v were tougher and had thicker plates; with AGM I don't believe there is any difference in hardiness and just it's different shapes and sizes.)

But aside from not making the same choice on the 6v AGM vs. the 12v, I think your idea is sound.

(If you want more ah, but not as much as four 6v; then you could do 3 Lifeline Group 27 for 300ah/186#, three Full River DC115-12B for 345ah/218#, or three Lifeline Group 31XT for 375ah/222#).

I think if it were me I'd do either the two Lifeline GPL31XT (250ah) or the two Full River DC115-12B (230ah). I'd go with Lifeline myself these days but I mean these two are roughly equivalent. You get a little extra in the ah department, not much more weight than the two 6v (if any) and a bit of redundancy of one battery craps out for some odd reason.

[chin_k]

AGM allows you to mount it in any orientation you want, and you never (rather, you can't) add water to it. It is an advantage when you need to install it sideway due to dimension constraint, or if you want to have it indoor, or if you do not want the hassle of having to check the flooded cells. Another advantage is that I can easily transport it via airline, unlike the flooded battery type (I know that is one of the most important advantage of AGM for us )

[Blue~Go]

I don't think 68's planning anything but AGM (or did I misread?). And Chin_k, good to know in case he plans to add wings