In relationship to say their 8-D battery, this is the answer I got...Justin Godber 12:48 PM (0 minutes ago) to meWhen you talk about 1 battery vs. 2 six volts there is no advantage or disadvantage either way. The only advantage is the 6 volts are much easier to move around by yourself. When you get into a 6 or 8 battery bank of six volts you can physically get more amp hour into the same space as the 8D’s using 6 volts. Example for the GPL-4CT, you can fit 3 in the place of 1 x 8D. If you had 2 x 8D’s you could fit 6 x GPL-4CT’s. GPL-4CT x 6 is 660 amp hour whereas 2 of the 8D’s would be 510 amp hour within the same footprint.I knew this twenty years ago. But the superstition about "Golf Car" being a better battery somehow, just will not disappear. The FOOTPRINT may be the deciding factor for many people. But as far as plates and general construction goes, choosing a 3-cell battery doubles the number of series cables neededNuff Said

"easier to move around" is a big benefit to GC-2 and one can often find better pricing on them.

MEXICOWANDERER wrote:In relationship to say their 8-D battery, this is the answer I got...Justin Godber 12:48 PM (0 minutes ago) to meWhen you talk about 1 battery vs. 2 six volts there is no advantage or disadvantage either way. The only advantage is the 6 volts are much easier to move around by yourself. When you get into a 6 or 8 battery bank of six volts you can physically get more amp hour into the same space as the 8D’s using 6 volts. Example for the GPL-4CT, you can fit 3 in the place of 1 x 8D. If you had 2 x 8D’s you could fit 6 x GPL-4CT’s. GPL-4CT x 6 is 660 amp hour whereas 2 of the 8D’s would be 510 amp hour within the same footprint.I knew this twenty years ago. But the superstition about "Golf Car" being a better battery somehow, just will not disappear. The FOOTPRINT may be the deciding factor for many people. But as far as plates and general construction goes, choosing a 3-cell battery doubles the number of series cables neededNuff SaidLifeline has basically debunked the constant myth on this forum that a 8D 12V is BETTER than a 6V GC battery according the first bolded text.In a nutshell BOTH the 6V GC battery AND the 12V 8D cousin IS the SAME as far as construction/quality, ect.As far as the second bolded text, while the use of 6V GC batts will require an additional external "interconnect" cable, it is no worse than all of the LEAD INTERNAL "interconnects" which are INSIDE the battery.Not to mention If one does their homework you can come up with very nice heavy interconnects to use between the 6V batteries which will easily be better than the all lead internal interconnects.Folks SKIMP on the interconnects which leads to the myth that 6V batteries are not as good as the 8D 12V battery.I made 1/0 interconnects from the leftover wiring I had left from my Inverter connection.. Most folks opt for 2 ga or even 10 gauge and wonder why they encounter a large voltage drop and blame it on the 6V batteries.. USING STOUT INTERCONNECT CABLE takes care of most issues with GC battery resistances. Not to mention folks whine about having to "maintain" the battery interconnects, IF THEY DID IT CORRECTLY THE FIRST TIME THEY WOULD NOT HAVE TO KEEP REDOING IT!!!Folks fail to use a bit of GREASE on the battery terminals and then whine about having corrosion at the terminals. I use "NoALOX" which is a electrical grease which was designed to interface electrical connections between copper and aluminum, copper to copper, aluminum to aluminumNoALOX prevents moisture and even acid from getting between the battery terminal and the interconnect. Do it right the first time and never need to do it again.Couple of other points..GC batteries ARE lower cost per lb and per Ahr than the 8D, I see no advantage to paying more for a 8D when it has the same electrical and mechanical characteristics as the 6V GC according to Lifeline.GC batteries ARE EASY to find and available pretty much everywhere, 8Ds not so much.GC batteries are half the weigh of 8Ds (70 lbs for GCs vs 140 lbs for 8D), therefore much easier to handle or move, I would rather handle 70 lbs twice before moving 140 lbs ONCE.GC batteries often can be used in spaces and configurations that 8Ds WON'T FIT without major alterations so therefore GCs are pretty much a "drop in replacement" for a group 24 or group 27 12V two battery configuration..Carry on..

However, they are comparing 1 8D battery to 2 6V batteries. The 8D is substantially larger and likely not a fair comparison to a standard 12 V deep cycle RV/Marine battery. He even admits that 3 6V's would fit in the same space so, logically, the 8D should have 1/3 more plates or similar parts a pieces than 2 standard 6V's.

If it is fair to say you can get 6 6s in place of 2 8Ds then why isn't it fair to say you can only get 2 6s in place of 1 8D ?(unless you can find a way to use three 6s :)--yes we had threads about that )

WHEN I ASKED LIFELINE ABOUT THEIR GOLF CAR BATTERIES

Harvey51
Explorer
Jan 07, 2019
In any comparison of 6v vs 12v batteries, I think it should be mentioned for the understanding that comparing amp hours is tricky. The amp hour is not a unit of energy. Electrical energy is measured in watt hours or volt-amp-hours. So a 100 amp hours in a 6 volt battery is 6x100x1 = 600 watt hours. Compare to 100 amp hours in a 12 volt battery: 12x100x1 = 1200 watt hours. It means you need two 6 volt batteries in series to equal one 12 volt battery with the same amp hour rating to have the same energy storage.
pnichols
Explorer II
Jan 03, 2019
H20ENG wrote:
One of the best upgrades I did to my old toy hauler was replacing the 2 "marine deep cycle" batteries with GCs. That and LEDs made for several days without running the gen for a recharge.
The new rig came with true deep cycle 12v batteries. Someday GCs will take their place.

Why do you consider, say, X amp hours of 6V GC batteries to be preferable to X amp hours of true deep cycle 12V batteries?
H20ENG
Explorer
Jan 02, 2019
One of the best upgrades I did to my old toy hauler was replacing the 2 "marine deep cycle" batteries with GCs. That and LEDs made for several days without running the gen for a recharge.
The new rig came with true deep cycle 12v batteries. Someday GCs will take their place.
CA_Traveler
Explorer III
Jan 02, 2019
stevenal wrote:
I have two 12 volt batteries so that if one fails I can disconnect it and still be operational. With 2 6s you're out of luck.
Yes but the advantage is minor IMHO. A short will likely wipe out both batteries. My batteries have always lost capacity which serves as a red flag for replacement.

Batteries are available everywhere in the US so I don't see a significant issue with a failing battery of whatever voltage. Inconvenient of course. Plus the advantages of deep cycle batteries for me far outweigh other types for the house battery.

Case in point: My son's 3 year old 6V GC battery have lost capacity due to lack of maintenance. We just installed additional solar and he's talking new Trojans and better maintenance next fall when he will again be dry camping. In the meantime they are adequate.

If upgrading from 12s to 6s be sure you have room including height. 6s are higher for a reason - There is more space under the plates allowing for more sloughed lead before reaching the plates resulting in longer life.
Atlee
Explorer II
Jan 02, 2019
When is the last time you have had one of two batteries unexpectedly fail?

I haven't heard of any of my friends who have dual batteries tell about a single battery failure.

Should one of my GC-2 6 volt batteries fail unexpectedly, then I'll know better, and may do something different next time.

Of course, my problem is the cost of two 12 true deep cycle batteries is a bit much. My two 6 volt batteries are relatively cheap.

stevenal wrote:
I have two 12 volt batteries so that if one fails I can disconnect it and still be operational. With 2 6s you're out of luck.
wa8yxm
Explorer III
Jan 01, 2019
I have a dual meter carbon pile load tester.

If battery bank is ackting "Funkey" (IE not holding charge) I start by isolating a battery or all of them. and then hook 'er up and test. Battery by battery.

The Dual meter tester (500 amp) is not hefty enough to do a PROPER test on a pair of GC_2's (That takes 600-700 amnps draw) but ... Well if they test BAD. they are.
prairie_camper
Explorer
Jan 01, 2019
stevenal wrote:
I have two 12 volt batteries so that if one fails I can disconnect it and still be operational. With 2 6s you're out of luck.

I’m curious to know how you monitor your batteries? Do you watch them constantly, how do you know if one is failing? Do you separate them if away from the RV for awhile? Because if one starts failiing internally and shorts out it’s taking the other one with it! You would have to be there at the exact moment it was happening to save the other one.:)
wa8yxm
Explorer III
Dec 31, 2018
I too am interested in the Full Discharge explanation
The myth with Ni_Cads was that you had to do that or they would develop memory (NO. they don't. at least not in human use They do in orbital satellites but that's about the only place).

WHen you look up Gauge. this is for guns not wire but the concept is the same

You case a bunch of balls the same diamater as the barrell of the gun
Then you dropped them one at a time on a scale counting

1-2-3-4-5-6-7-8-9-10 and the scale tripped over the mark. That's a 10 Ga Gun.

THis applies to all shotgund dave the .410.. that is a caliber (Size in inches o.410)

Same with wire. basically if you measure off say 12 feet of 12 ga and 10 feet of 10 ga.> Same weight.

there is specific weight and you cut that much wire and measure it's length to find the gauge.

That said I think wires are shrinking.
stevenal
Nomad II
Dec 31, 2018
I have two 12 volt batteries so that if one fails I can disconnect it and still be operational. With 2 6s you're out of luck.
H20ENG
Explorer
Dec 31, 2018
MEXICOWANDERER wrote:
Other Lifeline
I used a 50-watt incandescent lamp, discharged it totally then jammed 14.4 volts into it. 164 ampere hours if I remember correctly. It's rested voltage is .06 less than the T

Can you explain why you discharged it fully before recharging? I thought this was bad for all except NiCads :)
Were you just seeing how much it had stored without being charged for so long?