Two 6 volt vs two 12 volt run time

Atlee wrote:
Where did you get the true deep cycle Grp 31 12V AGM? How many amps did it have? And how much did it cost?

I'd prefer a true deep cycle 12V battery, not to be mistaken for a deep cycle marine battery, over a par of 6V golf cart batteries.

I'm not the one you asked the question of, but here's the Group 31 12V AGM deep cycle battery that we have a couple of - in a balanced parallel hookup configuration - in our RV ... for a total of 230 amp hours:

http://www.fullriverbattery.com/product/batteries/DC115-12

They weigh about 72 lbs. each, and have a 7 year warranty. I purchased these at a local battery supplier, who took my still working 8 year old Group 29 12V AGM deep cycle batteries as a core charge.

I actually went with an Optima blue top group 31. It is 75Ah and cost about $225.

I compared it to basic wet cell 6v batteries that were recommended and they totaled about 85Ah and cost around $200, but I would have had to do a modification to extend my battery hold into my one outside storage hold to fit the 6v batteries. For me, the difference wasn't enough to give up that space.

I've been really happy with it. I can go 4 days without dropping the battery at all. I will run out of fresh water before I take the battery below 80%.

That's why I say it's dependent upon the particular usage. This works perfect for me. As for durability, my engineer boss has been running one in his RV for a good 12 years now with no replacement.

I did actually get mine replaced when I had my engine rebuilt - they accidentally wired the choke to the house battery and bypassed the ignition shut off. It ran down the house battery completely. When I took it back to the shop, they recommended I change it out (it did recharge fine). I was 1 week out of warranty and they went ahead and accepted it.

Where did you get the true deep cycle Grp 31 12V AGM? How many amps did it have? And how much did it cost?

I'd prefer a true deep cycle 12V battery, not to be mistaken for a deep cycle marine battery, over a par of 6V golf cart batteries.

But I have seen any that are cost effective for me yet.

toedtoes wrote:
I found that available space and maintenance mattered also. I had limited space for batteries unless I modified the space. By going with one group 31 deep cycle AGM battery, I got just about the same Ah as a pair of 6v wet cell, but it fit without modification and I don't have to deal with checking levels, etc. It has been more than enough power for what I need.

The truth is, which is best is dependent upon your particulars. Like most things in life, one size does NOT fit all. Going with one over the other doesn't make a person smart or dumb, right or wrong. Going with the one that works best for your situation makes you right and smart.

The problem is a 12 volt deep cycle marine battery is not a true deep cycle battery. Deep cycle marine's are hybrids. A little bit of starter battery, and a little bit of deep cycle battery.

travelnutz wrote:


12 volt deep cycle marine batteries in group 27 and group 31 are very widely available in all areas of the country in the farm, marine, many automotive stores, lots of tire stores, big box stores like Walmart's and Sam's Clubs etc we have been in and seen with our own eyes. Prices do vary a lot around the country as about everything is a lot higher priced west of the Rockies.

travelnutz wrote:
So true toedtoes! And, of course physical room size limitations for the batteries used is also ultra important. It's known that 6 lbs of brown excretion won't fit in a 3 lb bag even if you jump up and down on the pile trying to pack it down to smaller in size. Something will certainly give and what a mess!

That's what I meant by "available space".


I don't think one choice is better than the other. I just think one choice WAS BETTER FOR ME than the other. For someone else, the 6v batteries will be a much better choice. As with so many things, I have found that doing my own homework and basing my decisions on my actual particulars results in a much better outcome than simply asking a question and accepting the majority viewpoint or standard wisdom.

Bumpyroad wrote:

Gjac wrote:
From a practical sense I think you were informed correctly if you look at life cycles per cost. s.

the statement was "I was just informed that two 6 volt batteries would run the residential refrigerator many times longer than two 12 volt batteries. I wonder if this is just hype? "

where do life cycles per cost enter into that information? run many times longer was the claim.
bumpy

Don't most of us look at the cycles per cost when buying batteries? Or anything else for that matter? I think that is what he was trying to tell the OP. At least that is how I interpreted the explanation. I don't think he was talking in a purely theoretical sense of comparing AHs. That I why I said from a practical sense. Does it make sense to buy 12 v starting batteries or marine batteries that won't last as long as 6v GC batteries ? Or pay twice as much for a 12v deep cycle one that I has a comparable life?

larry barnhart wrote:
.. have asked this question before with no answers yet. When a 6 volt battery is bad how will the other 6 volt battery power a 12 volt system?

I'll give you an answer. It won't. But it's such an extremely unlikely event it's not worth worrying about. Golf carts wouldn't have 6v batteries if they failed all the time.

I think the problem comes when people try to wring every last amp-hour out of them, or don't maintain them properly. That will surely cause one to fail before the other. You're supposed to change them when they start getting weak, not when they fail.

We've had this discussions more than a few times:
6v v 12 2017
12v vs 6v.. which charge faster? 2014
12v or 6 Dec 2013
2- 12v or 6v June 2013
12v vs 6v batteries 2013
12v vs 6v batteries 2006
More 12v vs 6 2006
12v vs 6v 2010
Why 2 6? 2006

Anybody had one 6v fail?2010

maybe 12v is better 2010
12v vs 6v Feb 2010

So true toedtoes! And, of course physical room size limitations for the batteries used is also ultra important. It's known that 6 lbs of brown excretion won't fit in a 3 lb bag even if you jump up and down on the pile trying to pack it down to smaller in size. Something will certainly give and what a mess!

I found that available space and maintenance mattered also. I had limited space for batteries unless I modified the space. By going with one group 31 deep cycle AGM battery, I got just about the same Ah as a pair of 6v wet cell, but it fit without modification and I don't have to deal with checking levels, etc. It has been more than enough power for what I need.

The truth is, which is best is dependent upon your particulars. Like most things in life, one size does NOT fit all. Going with one over the other doesn't make a person smart or dumb, right or wrong. Going with the one that works best for your situation makes you right and smart.