Before spring I will be replacing our two 12V Walmart coach batteries. Our 7 year old rig has it's original Tripplite 2000 watt inverter/charger similar to THIS ONE. I was thinking of replacing the two 12V batteries with two 6V batteries as these forums seem to favor 6V in series compared to 12V in parallel. I called the maker of my inverter. The technical person there told me two 6V batteries in series will work just fine with the inverter.But I have a concern switching from two 12V to two 6V batteries, this in regards to the drop in amp hours. Assumed identical amp-hour ratings, two-6V will be 1/2 that of two-12V. Currently our inverter adequately supplies power to make a pot of coffee and watch TV with a sound system. Will two-6V batteries in series be able to meet those demands the same as the two-12V?In General....With a rig like ours that has a 2000 watt inverter and no solar panels, what benefits and drawbacks might there be in using two 6V batteries in series? Keep in mind that we almost never hookup to shore power. Battery charging is done while driving and when parked for days at a time, running the generator.Will it take more time or less time to charge 6V batteries?How does the physical size of a 6V battery compare to a 12V? I hear they are taller. Do they take up the same footprint in our battery tray?I am especially interested in hearing from people who made the switch from 12V batteries to 6V. Also, I'd appreciate your input on the best 6V batteries to buy, where to buy them, and what I could expect to pay per battery.Thanks!

Ron..I have had both set-ups and have gone from 12 to 6 in one of them, I currently use 3 12's. I can't go all techy on you here. I haven't the foggiest idea of the numbers. What I go by is...does it work?My power consumption is as follows: I have one small inverter, a 600W that I run almost constantly to charge computer,camera, drill, flashlight batteries. I do not use lights sparingly and have no LED's. If needed I run my furnace like a normal life thing. I live in northern BC and that means that the sun is lower than in the southern parts of the US as far as solar collection is concerned.I seldom am in a plug-in situation and have never had a problem. I did work for the NPS in the Mojave during a 10 week winter (cloud, rain, snow) and again, never ran short of juice.I do have 250W of solar, and currently 3 12V Napa Deep Cycle's that I bought 3 years ago in Needles.Meeting your own personal needs will depend on three things. What your own personal power habits are, how much solar you have and yes, the batteries. Get LOTS of solar. That will ensure your batteries get charged no matter what the weather conditions. If I had to choose between 2 6V and 3 12 V's..and that WAS my choice..I'd take the 12's every time. If I had the room, but I don't, I'd opt for 4 6V's. The 6's will be taller and much heavier. I'd suggest looking at NAPA because if you have a problem, they are 'everywhere'. And shop at a NAPA store..not a dealer. The pricing is quite different.Gary Haupt

If you are comparing 2x group 24 and 2x GC2, the GC2 will have ~30% more amp hours.Of course you can get larger 12v and higher rated 6v.6v tend to be a bit taller so make sure you have the headroom.

We, too, are charter members of the no-hookups-club. I use 4x300Ah 6v batteries. As far as I know, it makes no difference whether you use a 6v battery or a 12v battery so long as you end up with the number of ampere hours you need. People started using 6v golf cart batteries as they were an easy way to find true deep cycle batteries, as opposed to starter batteries.(For the technically inclined, there are neither 6v nor 12v batteries, only 2v batteries, either three or six to the case.)So, connecting my 6v batteries in series/parallel, I end up with a 12v, 600Ah battery bank which gives me 300Ah usable.The type of battery you use is VERY important. For camper use, you want true, deep cycle batteries. That is big, thick plates and lots of acid.AGM batteries are more expensive but can offer advantages of less maintenance, better vibration resistance, and the option of mounting sideways.When you start getting over 400Ah, you really need solar or shore power to assure a full charge. Even with the special wiring on my truck, it is hard to drive long enough to fully recharge a big battery bank.

True deep cycle 12 volt batteries are few and far between. 6 volt golf cart batteries are relatively inexpensive and will outperform your typical 12 volt battery for the same footprint.Dimensions are available on most battery manufacturers' web sites.Charging times will be the same unless you go AGM which will charge faster if your charging system has the capability. Of course if you add more capacity, you can use more power which means a longer charge time.If you don't have a multi stage charging converter, now is the time to do it. Your batteries will charge faster and last longer.I converted over to 6 volt Lifeline AGMs (GPL-4CT) a year ago. They are awesome compared to the OE 12 volt group 24s that came with the RV. I also have a Progressive Dynamics multi stage converter.The "best" batteries for lead are AGMs hands down and Lifeline is near the top of the AGM list (if not the top). Optimas (a popular automotive and marine AGM) aren't really suitable for RVs so pass on them. The down side? They cost me $600 for the pair.

Hi Ron,How much do you use the inverter and at what wattage? I'd favor AGM chemistry, and 12 volt wired in a balanced manner if you "push" the inverter hard a lot of the time.

Batteries: Two-6V In Series, or Two-12V In Parallel ???

garyhaupt
Explorer
Oct 13, 2014
Ron..I have had both set-ups and have gone from 12 to 6 in one of them, I currently use 3 12's. I can't go all techy on you here. I haven't the foggiest idea of the numbers. What I go by is...does it work?

My power consumption is as follows: I have one small inverter, a 600W that I run almost constantly to charge computer,camera, drill, flashlight batteries. I do not use lights sparingly and have no LED's. If needed I run my furnace like a normal life thing. I live in northern BC and that means that the sun is lower than in the southern parts of the US as far as solar collection is concerned.

I seldom am in a plug-in situation and have never had a problem. I did work for the NPS in the Mojave during a 10 week winter (cloud, rain, snow) and again, never ran short of juice.

I do have 250W of solar, and currently 3 12V Napa Deep Cycle's that I bought 3 years ago in Needles.

Meeting your own personal needs will depend on three things. What your own personal power habits are, how much solar you have and yes, the batteries. Get LOTS of solar. That will ensure your batteries get charged no matter what the weather conditions. If I had to choose between 2 6V and 3 12 V's..and that WAS my choice..I'd take the 12's every time. If I had the room, but I don't, I'd opt for 4 6V's. The 6's will be taller and much heavier.

I'd suggest looking at NAPA because if you have a problem, they are 'everywhere'. And shop at a NAPA store..not a dealer. The pricing is quite different.

Gary Haupt
time2roll
Nomad
Oct 13, 2014
If you are comparing 2x group 24 and 2x GC2, the GC2 will have ~30% more amp hours.

Of course you can get larger 12v and higher rated 6v.
6v tend to be a bit taller so make sure you have the headroom.
DiploStrat
Explorer
Oct 13, 2014
We, too, are charter members of the no-hookups-club. I use 4x300Ah 6v batteries. As far as I know, it makes no difference whether you use a 6v battery or a 12v battery so long as you end up with the number of ampere hours you need. People started using 6v golf cart batteries as they were an easy way to find true deep cycle batteries, as opposed to starter batteries.

(For the technically inclined, there are neither 6v nor 12v batteries, only 2v batteries, either three or six to the case.)

So, connecting my 6v batteries in series/parallel, I end up with a 12v, 600Ah battery bank which gives me 300Ah usable.

The type of battery you use is VERY important. For camper use, you want true, deep cycle batteries. That is big, thick plates and lots of acid.

AGM batteries are more expensive but can offer advantages of less maintenance, better vibration resistance, and the option of mounting sideways.

When you start getting over 400Ah, you really need solar or shore power to assure a full charge. Even with the special wiring on my truck, it is hard to drive long enough to fully recharge a big battery bank.
Dakzuki
Explorer
Oct 13, 2014
True deep cycle 12 volt batteries are few and far between. 6 volt golf cart batteries are relatively inexpensive and will outperform your typical 12 volt battery for the same footprint.

Dimensions are available on most battery manufacturers' web sites.

Charging times will be the same unless you go AGM which will charge faster if your charging system has the capability. Of course if you add more capacity, you can use more power which means a longer charge time.

If you don't have a multi stage charging converter, now is the time to do it. Your batteries will charge faster and last longer.

I converted over to 6 volt Lifeline AGMs (GPL-4CT) a year ago. They are awesome compared to the OE 12 volt group 24s that came with the RV. I also have a Progressive Dynamics multi stage converter.

The "best" batteries for lead are AGMs hands down and Lifeline is near the top of the AGM list (if not the top). Optimas (a popular automotive and marine AGM) aren't really suitable for RVs so pass on them. The down side? They cost me $600 for the pair.
pianotuna
Nomad III
Oct 13, 2014
Hi Ron,

How much do you use the inverter and at what wattage? I'd favor AGM chemistry, and 12 volt wired in a balanced manner if you "push" the inverter hard a lot of the time.
Dakzuki
Explorer
Oct 13, 2014
Good battery info here:

12 Volt Side of Life Part 1
tenbear
Explorer
Oct 13, 2014
ron.dittmer wrote:

But I have a concern switching from two 12V to two 6V batteries, this in regards to the drop in amp hours. Assumed identical amp-hour ratings, two-6V will be 1/2 that of two-12V.

Your assumption of identical amp-hours is in error. Unless it is an unusually large 12v battery, expect a rating of 90-115AH. 2 in parallel will double that.

The 6v golf cart batteries have a rating of 235AH, so 2 in series will have that same rating, 235AH.
ron_dittmer
Explorer II
Oct 13, 2014
tenbear wrote:
ron.dittmer wrote:

But I have a concern switching from two 12V to two 6V batteries, this in regards to the drop in amp hours. Assumed identical amp-hour ratings, two-6V will be 1/2 that of two-12V.

Your assumption of identical amp-hours is in error. Unless it is an unusually large 12v battery, expect a rating of 90-115AH. 2 in parallel will double that.

The 6v golf cart batteries have a rating of 235AH, so 2 in series will have that same rating, 235AH.
So the 6V are twice that of 12V to begin with? Very interesting.
DiploStrat
Explorer
Oct 13, 2014
ron.dittmer wrote:

So the 6V are twice that of 12V to begin with? Very interesting.

Not specifically. There is nothing about a 6v battery that gives it an inherently higher ampere hour rating, but, as a matter of fact, most manufacturers make larger 6v batteries than 12v batteries.

Consider this link to: Lifeline's AGM RV batteries

You will see that there is an overlap in the 100 - 200 Ah range, but if you want 300Ah and up, your only option would be a pair of 6v batteries.

Finally, a 12v, 250Ah battery weighs in at over 125 Lb. A pair of 6v at 60lb. each might be a lot easier to work with.
tenbear
Explorer
Oct 13, 2014
There is one small difference between 12v and 6v batteries that make the 6v more efficient. Each 12v has 6 cells while the 6v has 3 cells, so more volume of the 12v is taken by partitions.