# Marine Batteries?



## dkinkela (Mar 14, 2009)

I'm going to replace the batteries on my outback. I've read some posts on battery charging, but haven't seen much on battery types. I've heard some people speak of marine batteries. Does it matter much?

Thanks


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## Oregon_Camper (Sep 13, 2004)

There are many version of this answer, so I will try the short and sweet...of course YMMV

Camping with power...don't "dry" camp - Stay with 1 x 12v battery

Camping 50% hookups & 50% dry camping... go with 2 x 12v batteries

Camp >90% dry with occasional hookups...go with 2 6v deep cycle battery (Trojan 125's or Interstate U2300)

Here is a great web site to really educate you on battery details.
http://www.ccis.com/home/mnemeth/12volt/12volt.htm


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## Ghosty (Jan 17, 2005)

Oregon_Camper said:


> There are many version of this answer, so I will try the short and sweet...of course YMMV
> 
> Camping with power...don't "dry" camp - Stay with 1 x 12v battery
> 
> ...


I would have to caveat that answer a little bit and not say that its the number of times BUT the number of days...

If you DRY camp for less then 48 hours and use the trailer sparsely (and its not in the middle of winter where the heater motor will wipe you out) - then yes, 2 x 12V will be fine...

BUT - anything over 48 hours - regardless of how many times a year you do it -- then you need 2 x 6V (Tojan 125s) ... with a 85watt solar cell and 2 x T-125's I can get 5 good days of dry camping ....

(To really do it right i would need 170 watts of SOLAR)


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## outback loft (Sep 22, 2008)

Ghosty said:


> There are many version of this answer, so I will try the short and sweet...of course YMMV
> 
> Camping with power...don't "dry" camp - Stay with 1 x 12v battery
> 
> ...


I would have to caveat that answer a little bit and not say that its the number of times BUT the number of days...

If you DRY camp for less then 48 hours and use the trailer sparsely (and its not in the middle of winter where the heater motor will wipe you out) - then yes, 2 x 12V will be fine...

BUT - anything over 48 hours - regardless of how many times a year you do it -- then you need 2 x 6V (Tojan 125s) ... with a 85watt solar cell and 2 x T-125's I can get 5 good days of dry camping ....

(To really do it right i would need 170 watts of SOLAR)
[/quote]

To add to it, I have found that the 12 volt deep cycles that I have been working with actually have more amp hours than two 6 volts in parallel. I have been going back and forth with my solar installer on this and he is even reccomending group size 31 12 volt deep cycles over twin 6 volts. I am running one group size 31 12 volt lead acid battery, and a group size 31 12 volt AGM battery, and each battery has the lifespan to get me 6-8 days, depending on my usage. (and this is without the 350 watts of solar panels I have on the roof) I have had the camper in storage for the past 2 weeks with the 1000w inverter on standby with the tv, dvd player and DVR satellite box on, along with my outdoor step light on 24/7 and I dont even come near draining on battery. Once the sun goes down and my solar is not doing anything, I will go down to 12.8 volts by the morning with this setup.

(And I have a 175 watt panel on the way to use as a moveable panel....so i will be totaling 525 watts of solar power)


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## webeopelas (Mar 11, 2006)

You want a deep cycle not a marine. It will work but Marine batteries are kind of a hybrid between a deep cycle and an automotive battery.

Auto is made to discharge high amps in a short amount of time (to drive the starter)

Deep cycles are designed to discharge lower level of amps over a greater amount of time and they hold up to a deep discharge better than autos.

Marines are kind of in the middle so it can run the starter on the boat while being useful for onboard accessories or trolling motors.

You've got plenty of other advice above on how many.


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## DernMooseAK (Apr 16, 2004)

I would just go with 2 group 24 deepcycle batteries. We used that set up for 5 years. Most of our camping here in Alaska is dry camping. We could do 3-4 days with power to spare, and the furnace runs most nights at least 2-3 times. They died this year partly my fault for leaving them in to late last year, with no charge. So I got group 27's to replace them.
And yes we run a TV/DVD for the wife and I, and Dual DVD players for the kids.


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## phxbrit (Jul 24, 2007)

We had some bad luck with Interstate batteries (2 x 6v) only lasting 18 months. The charger threw an error and wouldn't charge them anymore. We recently replaced them with a pair of Trojan T105. I wanted to go with the T125, but the sales guy talked me out of it. He commented that you are really only getting about 6.5% more capacity out of the battery but they cost significantly more.


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