2 6v Batteries vs 2 12v batteries

[D A Busman]

I currently have 2 end of life 12v batts in my 2006 3400RL Monty. I am thinking about replacing them with 2, G2 6v batts. I usually am hooked up to power but do spend nights while traveling as well as a few days a year boondocking with access to a generator. Any thoughts on good/bad idea? Or input on past/professional experiences would be helpful.

[Charlie 3931fb]

Originally Posted by D A Busman

I currently have 2 end of life 12v batts in my 2006 3400RL Monty. I am thinking about replacing them with 2, G2 6v batts. I usually am hooked up to power but do spend nights while traveling as well as a few days a year boondocking with access to a generator. Any thoughts on good/bad idea? Or input on past/professional experiences would be helpful.

Hey there,

I was told by a battery pro that because we are on shore power all the time just to stay with 12 volt and go with 2 batteries and that would work out just fine.


Charlie

[scuba dude]

Same here!

[AZ Traveler]

Two golf cart 6v batteries will provide more amp hours of energy than two 12v batteries. Important if you boondock not so much if you don't.

It's pretty easy to convert.

[ChuckS]

The GC2 batteries will outlast any wet cell 12 volt battery. I’m on my sixth season with two of them. AGMs are nice too but $$$ and then of course you’ve got lithium but that would most likely require a converter upgrade

[Creeker]

Either or for your use will be just fine. I would advise going with group 27 size if staying with 12 volters. Stay away from the cheap group 24 dual purpose. You can get more bang for your buck with 6 volt but true deep cycle 12s are available and just as good as 6 volt.

[mazboy]

just go to costco or sams and pick up 2 6 volt battteries. always changes batteries together.

here is one of many articles:
https://www.rvhometown.com/6-volt-vs...-rv-batteries/

[luckeyd]

Something to think about, if one of the 6v batteries goes bad, you are stuck. If one of the 12v go bad everything still works just not for as long.

[Charlie 3931fb]

Originally Posted by Creeker

Either or for your use will be just fine. I would advise going with group 27 size if staying with 12 volters. Stay away from the cheap group 24 dual purpose. You can get more bang for your buck with 6 volt but true deep cycle 12s are available and just as good as 6 volt.

Hi,
I don't know if you would agree with what I did, but on my toyhauler we went with 2 12 volts AGM Glass Mat group 27. These are the batteries that you can hang upside down if you had to. That trailer in 5 years old and still on same batteries. Our new Montana we got Interstate Batteries Group 27 RV/Marine they came with the unit. They never asked me about the batteries when we got the trailer. (Montana)

Charlie

[twindman]

Originally Posted by AZ Traveler

Two golf cart 6v batteries will provide more amp hours of energy than two 12v batteries. Important if you boondock not so much if you don't.
It's pretty easy to convert.

I disagree with this. Everything I have read says parallel batteries - add the amp hours. Series - add the voltage. So an individual 6V usually has more AH than a 12V. But in parallel, the 12V will have much more AH.

[Jt_Hd]

Originally Posted by twindman

I disagree with this. Everything I have read says parallel batteries - add the amp hours. Series - add the voltage. So an individual 6V usually has more AH than a 12V. But in parallel, the 12V will have much more AH.

A quick look at batteries plus website shows $120 x 2 for 2 6v batts at 215 amp hours for $240 total. This equates to 215 amp hours at 12 volts.

2 group 27 12v batteries is $110 x2 ($220) and they are 90 amp hours each which comes out to 180 amp hours at 12v.

TL;DR
6v = $240 for 215AH @ 12v
12v = $220 for 180AH @ 12v

https://www.batteriesplus.com/productdetails/sligc110
https://www.batteriesplus.com/produc...le/12/sli27mdc

[AZ Traveler]

Originally Posted by twindman

I disagree with this. Everything I have read says parallel batteries - add the amp hours. Series - add the voltage. So an individual 6V usually has more AH than a 12V. But in parallel, the 12V will have much more AH.

You are correct, you add the ah connecting two 12v batteries where you do not hooking two 6v in series. What you are missing is the 6v golf cart batteries are typically 225-240 ah compared to a group 27 12v with an ah rating of 100 or less.

[D A Busman]

[QUOTE=Jt_Hd;1183272]A quick look at batteries plus website shows $120 x 2 for 2 6v batts at 215 amp hours for $240 total. This equates to 215 amp hours at 12 volts.

2 group 27 12v batteries is $110 x2 ($220) and they are 90 amp hours each which comes out to 180 amp hours at 12v.

TL;DR
6v = $240 for 215AH @ 12v
12v = $220 for 180AH @ 12v

So dumb question here... for $20 I get 35AH more. How much difference is 35AH going to make running my furnace fan for a night and or a few lights?

[AZ Traveler]

About 35 ah worth.

Sorry easy smart ass answer.

The additional 35 ah actually buys you about 17.5 ah usable. If your furnace blower motor draws 10 amps, the extra power provides about an additional 1 hour and 45 minutes assuming the motor is running constantly.

[Jt_Hd]

Originally Posted by D A Busman

So dumb question here... for $20 I get 35AH more. How much difference is 35AH going to make running my furnace fan for a night and or a few lights?

180 x 1.2 (20%) = 216. So about 20% more.

Also, 6v deep cycles tend to be a lot more forgiving when drawn down below 50% due to larger and more spaced out plates over 12v units.

[D A Busman]

You have all helped a bunch and I appreciate it a bunch!! (Even AZ and your humor I got it!!) THANK YOU ALL!!!

[Dam Worker]

I went to dual 6V batteries but I boondocks a couple times a year. I only had a single 12V battery and it would be dead in the morning after having to run the heater and other things all night. The 6V batteries have a lot thicker plates due to only having half the number of cells and can be charged and discharged many more times then the 12V batteries. A lot more amp hours also available if I remember correctly. I like the Trojan brand even though you may have to pay more. I have had them in my other unit and got about 7/8 years out of them. If you do get the AGM batteries they have some advantages over the wet cell type. In talking to the manufacturer of my converter he said there was a setting on the converter to put the optimum charge on the AGM’s.
Happy and safe roads to you.

Tom Marty

[twindman]

Originally Posted by Jt_Hd

A quick look at batteries plus website shows $120 x 2 for 2 6v batts at 215 amp hours for $240 total. This equates to 215 amp hours at 12 volts.

2 group 27 12v batteries is $110 x2 ($220) and they are 90 amp hours each which comes out to 180 amp hours at 12v.

TL;DR
6v = $240 for 215AH @ 12v
12v = $220 for 180AH @ 12v

https://www.batteriesplus.com/productdetails/sligc110
https://www.batteriesplus.com/produc...le/12/sli27mdc

I guess my memory isn't too good. I thought 12v batteries were around 180-200 AH. I haven't bought one for 7 or 8 years. I use 6V and have a marine switch so I can flip between the 6 V or the 12 V. Just use the 12V for a 'spare'.

[Texan]

The reason why dual 6-volts are better than two twelves is [1] Have thicker battery plates [2] More amp hours [3] Can be discharged deeper than 12-volt without plate damage [4] Much more battery cycle life. Trojan T-105 batteries are considered one of the best wet cell golf cart batteries on the market. If you properly maintain the batteries then you will most likely get 7-10 years from them. When running 6-volts in series you should use 2/0 wire and 4/0 wire if running 4 batteries together.