Battery use

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.


Nov 27, 2012
I'm a first time user. My question is, I have a 2004 Coachman Concord 27' it only has 1 12volt coach battery  Not much space in the battery compartment. Would 2 deep cycle 6 volt golf cart batteries be a better choice or stay with one 12 volt deep cycle.  Thanks for your thoughts!!
It depends on how you camp and what you need the batteries to do for you.
Do you only stay in parks with hook ups, then it really doesn't matter what you use. Dry camping would definitely benefit with the two 6v. They usually are around 225 ah vs 100 ah or so for most 12v DC. 
JiminDenver said:
It depends on how you camp and what you need the batteries to do for you.
Do you only stay in parks with hook ups, then it really doesn't matter what you use. Dry camping would definitely benefit with the two 6v. They usually are around 225 ah vs 100 ah or so for most 12v DC.

They are also quite large. Each one is almost the size of a group 24. I don't doubt that they give you much better performance in a four battery (series/parallel) setup. But I, like you, are strapped for space. I am thinking about adding a second group 24, in my hanging wardrobe space. Had I known about the amp hour ratings of the golf cart batteries before I just bought my 12v group 24, I would have bought a couple of 6s. Now than I am stuck with 12v, I have to go that way. Live and learn. Next coach...
If you have room for two 6v's, then you also have room for two 12v batteries. Either method would give you at least 2xy more amp-hours IF YOU NEED THEM. If you don't camp without shore power, you probably don't need more.

There are a number of different battery case sizes, so if you don't have room for one style, another might be possible.  You can use a larger size and stick with just one battery. For example, a Group 29 or 30 size 12v battery will typically have 50-60% greater capacity than the usual Group 24 size that most trailers come with from the factory. Or perhaps you can find a taller, skinnier battery that will allow two to fit and double (or more) your power.
I do not entierly disagree with the "It depends on how you camp" statement but there is more.. Some facts

For optima batteries multiple all capacities by 60% (0.6)

Group 24, about 75 amp hours
Group 27, just shy of 100
Group 29 Just over 100
Group 31 about 120
GC-2 pairs, 230  (no optima that I know of)

NOTE these numbers do not matter if you get flooded wet, maintenance free or AGM, save for Optima they are all right close to the numbers I gave you.

Additional.  Most Group ## batteries are "Marine/Deep Cycle"  This is a starting battery and if it's run down too far.. Tends to not recover well.

GC2's are True Deep cycle and do a much better job of recovering from an "OH S***!" discharge level (below half for GC2).

But wait, there's more....

Many trailers have low end single stage converters. Older ones it is often the Magnetek 6300, which is known for it's ability to kill batteries.. The Flooded wet types are a bit harder to kill, but ....  If you have a Magnetek.. UPGRADE.. If you have a single stage, Consider upgrade.
Thanks so much for all the info on 6 and 12 volt batteries. I'll shop around to see if I can get 2 batteries that fit my compartment. I am planning on doing some boondocking and would like as much power as I can get.
Thanks again!!!!
Dittos. Big thanks on the battery tips.  Always wondered why the wannabe roach coach needs a new marine starting battery each year which usually coincides with the 12 month warranty running Now I know. Any tips on where to buy the ones we need? Also which one is it for them who only mess with one battery. I sorta got lost on the arithmetic table. 
IF you find you can fit a pair of GC-2 Golf Car batteries. Try Sam's... Though a Trojan is better, it's also a whole lot more expensive.. Sam's are far cheeper, enough so that I think the difference in price carries the day.
Ok got it thanks. Dont like buying batteries but cant wait to try it. Knew there was something fishy bout the marine batteries zonking out so pun intended.
A few things about adding batteries.

When adding a matching battery, you don't want the older battery to be very old with diminished capacity. It can drag down the new good battery. They should at least be of the same size and amp hours.
When adding extra battery somewhere else in the rig, you need to keep the runs of wire close to the same for both banks so that they are balanced. Make sure you use a heavy enough wire for the distance.
Sealed batteries are fine inside the rig but flooded batteries have to have ventilation.

When dry camping, conservation is as important as adding extra capacity. We currently have a single grp 27 battery with 95 AH and even though we run the furnace nightly in temps as low as the 20s, we have never dropped down to 50% of capacity, much less drained the battery over night. We do this by using as little power as we can without feeling like we are still tenting. Things like...

We replaced all of the lighting with inexpensive ebay led lights for $50. We now use the lights at will and never worry as they use a 5th of the power the regular bulbs do. We use to not use the house lights at all, instead used HF puck lights at night.
We turn off the hot water heater and pump when not in use. We keep a water jug in the trailer for small uses like coffee so we don't need the pump and it doesn't wake honey up at 5 am. On really cold nights, we even shut down the fridge.
Anything that can be charged by 12v gets charged in the truck over night. That includes cell phones, computers, mp3 players, portable DVD players and small TVs. I have never drained our trucks battery using it for charging.
At night we seal the windows with Glad press and seal and then drape heavy bath towels over them. This cuts down on heat loss and the furnace runs much less. We set the furnace at 65 at night.
Some people can use portable propane heaters such as the Mr Buddy line or Olympic wave because they don't use the battery. I can't because of the altitude we camp at but it is a option if it works for you.
The last thing is to have a way to keep the battery charged. We currently have 3 ways to do this. Solar, a Generator and as a last resort, jumper cables to the truck idling for a hour each day. Batteries do best when not left discharged for long periods of time.

Top Bottom