Battery Question

Maybe go with two 6 volt cart batteries instead.

You can without issue, but look at the amp/hr ratings and if they are true Deep Cycle or the Marine mixed use batteries. You may find that a pair of 6 volt GC-2 Batteries would give as many or more amps and being true deep cycle batteries, longer service at a lower cost.

Leon54173 wrote:
We do a lot of dry camping and currently have 2 x 12v batteries in parallel. Batteries are approaching end of life and I’ll be replacing them shortly. I have the space for a third battery, and am thinking of going with 3 x 12v to maximize amp hours. However, I’ve never seen or read about such a configuration. Is there any reason I shouldn’t do this?

I ran with three 12s (27s) for a time. Worked ok. Only "issue" was no way to really balance the charging and draw, so the middle battery wasn't being worked quite as hard as the outer two. I swapped them around every few months so they took turns being in the middle. You don't have to be so fussy to get the benefit of more AH with three than two though.

It depends if you are using three 24s or three 27s whether it beats a pair of 6s for AH.

A different issue from AH is the 27s vs 6s thing, but that is a whole different topic, covered many times here in past threads. You can find those if you are not familiar with all that business.

No problem adding a 3rd battery,....for exactly 1/3 more amp hrs.
And if they are group 27s, you will then have approx. 315 AHs, 105 more than you will get out of 2 std 6v golf car batteries.

The imbalance mentioned is not worth even talking about. Connect the cables to the center battery, and no problem ! And if contacts are clean, there is no imbalance anyway,.....despite what the battery fanatics lead you to believe !

Depending on size and layout you might look at a pair of longer group 31 12v.

Not exactly perfect balance but note the main cable comes off each end of the stack and will serve you better than both coming off a single battery.



http://usbattery.com/info-center/configuration/configuration-8/

No problem.

Car jar batteries that are more cyclable are not cheap. If you plan to not add a bunch of new loads then your can stick with your existing brand as they have proven themselves for your own particular type of use.

Try to get the same alpha-numerical date code on all three batteries.

I have used 3,4, even 5 , 12v batteries in parallel

Use quality batteries, and good clean balance wiring

Absolutely no reason you couldn't go with three 12 volt batteries in a parallel configuration, whether it's the best solution is another debate altogether. From our experience, although we only had a pair of 12 volt batteries when we purchased our rig new, going to a pair of 6 volt golf cart batteries gave us better performance and increased longevity, drycamping and boondocking are our preferred method of RVing and we are pretty hard on our batteries.