Deep Cycle Marine Batteries

no , it will not harm anything to go bigger .
my pop always said " there is no substitute for cubic inches "
that adage is true for batteries .
the cheapest really good switch is 2 golf cart 6 volt GC2 batteries available everywhere including Costco and sam's club .
I went a different way because I replaced my batteries one at a time .
AGM construction batteries on my trailer and my truck .
I paid $ 140 each for exide edge AGM batteries at bimart / Oregon .
google AGM for the reasons to do AGM .
AGM are maintenance free , do not leak , do not off gas , have faster recharge , will take more abusive deep discharging , than conventional battery construction .
but two GC2 in series will give more capacity for less money than the AGM .
If I only had room for one battery I would use the biggest AGM construction battery .
exide EDGE are made in North Carolina and offer a few choices for this usage .
their website shows those options .

Trailer Life has a good article about batteries , they talk about batteries that I have never heard of but seem to be good for RV's.

for the cost. Interstate 6 volt deep cycle batteries @ 232amps, hard to beat.

Lillyputz

My opinion is you'd be BETTER serviced with a straight "deep cycle" instead of a marine/deep cycle (which means basically a modified starting battery). Unless you'll be using batteries to "start" something straight deep cycle would last much longer. Size is unimportant as long as you have the necessary room to install them/it.

jquattlebaum wrote:
My current battery is a 24M 550CCA 690MCA. Will it hurt if I go with a larger battery with more CCA and MCA?

"Marine" batteries are not true deep-cycle batteries since they are designed for starting under high loads. True deep-cycle batteries are designed to be able to discharge significantly (much lower than a marine battery), then take a full charge again, and again, and again...for years. Yes, you can kill them by discharging too deeply, just as any battery, but they will last much longer and give many more hours' use than "marine" batteries. If you boondock or dry camp much, do yourself a favor and grab a couple 6v golf cart batteries from Sam's or Costco. Best thing I've ever done for my FW. Adding one of those inexpensive 45w solar kits from Harbor Freight gives me about an extra 1-2 days' power when camping, too. By then, my tanks are full so I've got to leave anyway! :-)

Lyle

I had a pair of 6V marine deep cycle batteries I transferred to my RV. They had lived on a boat for 7 years. In winter a -30 c they sat disconnected. They were used to run everything on the boat and start a Yanmar diesel marine engine. I then got 4 more years out of them in the RV. All I did was maintain them properly.
I traded them at a Sams club in Texas and got 2 deep cycle 6V golf cart batteries. They are now going on 6 years old. I've traded 2 trailers in for newer ones that come with 12V. I give the 12V to the dealer and take my 6V with me.
So far so good.
CCA is a usless figure for an RV. The adage goes the thicker the lead the longer the life.

No there is no harm in upgrading as you described. However you should be made aware of the following:
- that M in 24M means it is primarily a starting battery not deep discharge
- find a dual duty battery that is D such as 24D or 27D, it's more of a dual duty battery than a starting battery
- if the battery label doesn't have a 20hr AH capacity rating it is not a deep cycle battery. CCA and MCA are not ratings that can be used for deep cycling ability directly, although bigger is better.

Downside is that a deeply discharged "deep cycle" battery can be damaged via charging with the chassis system.

Lots of outgassing.

I tend to avoid marine batteries for deep cycle RV use. I feel that a deep cycle battery will tend to support very occasional starting (like a generator, or jump starting the engine) better than start batteries (which is what marine batteries are biased towards) will support mostly deep cycle use.

But to answer your question, no, there is very little downside to a larger battery as long as you can charge it.

Brian

Deep cycle batteries are designed for deep discharge cycles. If you regularly discharge your battery while boon docking then a deep cycle battery may be a better option. If starting batteries are discharged frequently below about 50% of capacity then they tend not to last very long. Deep cycle batteries are more expensive, but are designed for most RV applications. I use deep cycle batteries on my boat for both my starting and house batteries.