motor home batteries

[Kerney]

I have had different opinons on what is better or will last longer, putting two six volt batteries versus two twelve volt batteries in my motor home to run the furnace etc. I understand one way I will run them in series and one way parallel. I have been told by the people at batteries plus that the six volts will last longer, not necessarily run things longer but I would not have to replace them as often as two twelve volt batteries because they are more rugged. Which of these ways would be the most benificial? I can see that if you run off of one twleve volt and it starts to get too low to run the furnace properly that you could switch to the other twelve volt battery where as if you have two six volt batteries you could not do this. Any body have experience with this?

86 Class A Cobra American 30.

[Kerney]

I have had different opinons on what is better or will last longer, putting two six volt batteries versus two twelve volt batteries in my motor home to run the furnace etc. I understand one way I will run them in series and one way parallel. I have been told by the people at batteries plus that the six volts will last longer, not necessarily run things longer but I would not have to replace them as often as two twelve volt batteries because they are more rugged. Which of these ways would be the most benificial? I can see that if you run off of one twleve volt and it starts to get too low to run the furnace properly that you could switch to the other twelve volt battery where as if you have two six volt batteries you could not do this. Any body have experience with this?

86 Class A Cobra American 30.

[RV Wizard]

I personally like the two 6 volt verses 1 12 volt set up for the following reasons. With a six volt battery you have a wider cell area than with 12 volt. This will give you more available amperage and more durability than a tighter cell area. I think also the cost of a 6 volt is less than a 12 volt that is pure deep cell construction.

Mike & Amy, Fulltimers
RVSA Certified RV Technician
Dinasaur Board Distributor
No Wet Distributor
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Muffin our Shih Tzu
Ashley and Candi at school
2000 GulfStream 39' Scenic Cruiser on Spartan M.M. w/ 330 Cummins
99' Chevy 4x4 service truck NASCAR #3 & #8

[crewzer]

A series pair of 6V golf cart batteries (i.e., Trojan T-105's) have a great and deserved reputation as a rugged, dependable and cost effective 12 V RV battery bank. A pair together is rated for 12 VDC (nominal), 225 AH and 447 RC.

There's at least one rugged and true deep-cycle 12 V battery alternative -- the Trojan 31XHS. Individually, this battery is rated for 12 VDC (nominal), 130 AH and 225 RC. A parallel pair would be rated for 12 VDC, 260 AH and 450 RC -- slightly better than a pair of T-105's.

Due to a phenomenon known as the Peukert Effect, a parallel pair of 31XHS' would perform a bit better (perhaps 5% or so) than just adding their AH and RC ratings. This phenomenon does not apply to hooking batteries in series.

There are pluses and minuses to the T-105's and the 31XHS'. The T-105's are easy to find and cost a couple of dollars less than the 31XHS'. However, they're a bit on the tall side, and they must be used in series to supply nominal 12 VDC.

The 31XHS' are harder to find, and they cost more than T-105's. However, they're about the same size as a regular Group 27 battery, so they'll fit in boxes and locations designed for that size battery. Also, if required, they can be used separately and still supply 12 VDC each.

HTH,
crewzer

crewzer Y2K F250 4X2 SD CC SB XLT 5.4LV8 AT 4.10LS TT + Y2K "solar powered" Coleman Mesa

[This message was edited by crewzer on Fri October 10 2003 at 09:38 AM.]

[Gary RVRoamer]

Crewzer has it right, good advice all the way.

Kerney, you said something to the effect of using one 12V and then switching to the other when needed. That would not be a typical install, though it certainly can be done. Usually the two 12's are merely wired in parallel so they supply power together and get re-charged together. If you want to split them up, you will need an isolater and a big crossover switch. Switches are available for marine use (Perko makes some nice ones) and aren't real expensive. Personally, though, I'd wire them in parallel and keep all batteries online. You only get to use about half the amp-hours in a battery before the voltage drops seriously low and half od one battery isn't a great deal - only about 40 A-H on a size 24 and 50 or so on a 27 or 31.

Gary Brinck
2002 Dolphin LX - W22 chassis
2000 Chevy Tracker 4-Dr 4WD
Homebase in the Ocala Nat'l Forest near Ocala, FL

[r4blueticks]

Ok nobody still answered his question... It was will TWO six volts outpeform TWO twelve volts...

Not two sixs against one twelve... BUT TWO sixs against TWO TWELVES...

[Rainbow]

I replaced my 2 12v coach batteries with 2 6 volts from Sam's club. They will power things longer before needing to be charged. Have been in 3 yrs. now and still working well

[Kazoo Tom]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by crewzer:
A series pair of 6V golf cart batteries (i.e., Trojan T-105's) have a great and deserved reputation as a rugged, dependable and cost effective 12 V RV battery bank. A pair together is rated for 12 VDC (nominal), 225 AH and 447 RC.

There's at least one rugged and true deep-cycle 12 V battery alternative -- the Trojan 31XHS. Individually, this battery is rated for 12 VDC (nominal), 130 AH and 225 RC. A parallel pair would be rated for 12 VDC, 260 AH and 450 RC -- slightly better than a pair of T-105's.
</div></BLOCKQUOTE>

I think the above quote by Crewzer answers most of your question.

[r4blueticks]

Ok My bad,, I didnt read Crewzers reply completly... Good job and he answers All my questions..

[rogueii]

You can also call Trojan Battery, they have some good technical service people that have been very helpfull in the past.

[Rob Hentges]

I installed two trojan 6v batteries a few years ago and have been very happy. I also do a lot of primitive camping and have needed the batteries to run the furnace all night in below 20 degree weather.
One thing covered elsewhere, but not in this thread is the charging method. Initially my RV had the stock converter/charger. I replaced it with one that included the battery wizard. Prior to this, the batteries would lose fluid from being overcharged. Since using the wizard, the battery performance has been great.

[Lockman]

For those who have changed to (2) 6V, how many of you had to replace the battery cables?

Quite often, (in my case) they are not long enough to do the needed hook-up. Also, they have a different profile and may not fit in the battery hold-downs.

[kenbt]

I replaced the Winnebago 3 battery 12 Volt system for 4 6 volt T105 Trojans golf cart batteries. I was able to use all the existing cables without a problem and there were enough for the installation. I went from 375 AH to 450 AH and the golf cart batteries are designed to be run down and recharged many times vs 12 Volt deep cycle.

["007"]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by r4blueticks:
Ok My bad,, I didnt read Crewzers reply completly... Good job and he answers All my questions.. </div></BLOCKQUOTE>

Welcome to irv2 r4blueticks good to have you aboard.
You have nothing posted in your profile we need some info if we are to help you with what ever you have. Coach and chassis info can be posted in the signature block on second page click on upper right hand corner to find sign block.
Enjoy the forums and post often. "007"