Looking for new Battery(ies)...

[Sinclue]

The battery that came with our trailer (a Pep Boys special installed by the dealer) doesn't hold much of a charge any more.  We used to be able to go three nights, but now are lucky to make two (with reduced consumption on the second night).  As it doen't seem to be a particularly great battery we'd just as soon install something better (as befitting our wonderful trailers!).
What do people recommend?  We are in California and are pretty frugal with our electric consumption.  We don't run any inverter requiring items...biggest draw is probably heater fan.  Rarely even take our TV along.  I wouldn't mind having extra capacity since you don't know what tomorrow may bring. (Was that really me sitting in that tent lo those many years ago scoffing at those "softies" in their trailers? LOL).  What do other 2720SL owners do?  Anybody have two 6v or two 12v batteries in the battery compartment? Or does a dual setup require relocating batteries to the front?  Wouldn't  voltage drop be more of an issue if they were located in the front?  
A friend of mine has two batteries, but only one is installed.  He carries the other one in his van and when the first gets low he just swaps in the "fresh" one.  I guess if he wanted to stay longer he'd probably just buy another battery!
Any recommendations as to type and brands and installations would be appreciated.
Also. do people rely on the onboard charger to recharge their batteries (with shore or generator power) or do they add a supplemental charger?  I'm not sure my car battery charger is any better than the onboard one, but am not sure of the relative specs.  All my info on the onboard charger is in my trailer which is stored elsewhere.
Thanks
jim

I suggest you put 2 batteries on your trailer. I added a second one to my 2619 and found it greatly increased our 'dry camping' time. The 2619 batteries can mount on the tongue behind the propane tanks. Where you can mount 2 batteries together on your 2720SL will require study. The batteries should be mounted together where standard battery cables connect the 2 of them together, to minimize voltage drop.

The other choice you need to make is whether to use 2 12V batteries connected in parallel or 2 6V batteries connected in series to produce 12V. Do the research to find out which combination will provide you with the greatest Volt-Amp hours. You will probably find the 6V combination will provide the greatest number of hours, but that is not a given. It is based on the quality battery you select. Also, make sure you consider only the RV-type deep cycle battery to give you the greatest amp capacity.

With the right combination, you should be able to frugally use 12V power for up to a week's stay... the heater fan is your biggest drain, the refrigerator (on 12V) is the second (always operate on propane while dry camping). Make sure your convertor can charge 2 batteries, both plugged into 110VAC as well as while you are traveling on the road.

I have missplaced the link, but I have seen people using 2 6 volt golf cart batteries wired in a series, gave a lot of amp hours for the size. A couple of weeks ago I say a 5 vr that was using an electric fork lift battery, talk about amp hours! If I can locate the link on golf cart batteries I will post it.

Aaron

this spring I'm going to go to the dual 6V batteries wired in series for my 2619. If you wire 2, 12 volts in series, you'll have to convert to 24 volts. And from what I've read, wiring 2, 12VDC batteries in parrallel doesn't give you a whole bunch more useful amp hours that you get with the dual 6 VDC batt wired in series. I expect that I'll get close to 500 amp hours from the dual 6 volt in series set up.

I've got a customer that specializes in servicing the HD and industrial accounts here in Portland, and am going to buy the large capacity 6vdc industrial equipment batteries from him. they aren't that much more expensive than regular type 24's or 27's...

And the useful life will go up dramatically! I think I saw this discussed in Trailer Life a while back too...

anyway, that's my two cents worth.

Gregg

jp,
click on "Search" at the top of a page, then type in "Battery" or "AGM battery." Also type in "365" in the box showing the maximum number of days you wish to search backwards. This will bring up a lot of old posts since we have had a lot of discussions about types of batteries, battery installations, charging batteries and inverters.

As Paul H. suggested you should purchase a true deep-cycle RV battery as a replacement for your dead one. Your dead one that came from Pep Boys undoubtedly was a "Marine-RV battery" since that is the only kind of RV battery that auto parts stores sell. This hybrid is a battery some manufacturers market in an attempt to satisfy the needs of both RV owners and power boat owners. It is capable of producing a large surge of current for engine starting purposes (needed by a power boat or a motorhome) while possessing some deep cycle characteristics. "Deep cycle" refers to a battery that is designed to allow its stored energy to be almost completely expended between charging cycles. Since our travel trailers often stand unused for long periods of time, their batteries may lose most of their stored energy (their voltage drops as a result) until it's restored by recharging some time later - through current provided by a towing vehicle or a portable battery charger. True deep cycle batteries withstand this kind of neglect much better than automobile batteries or marine-RV batteries. The latter two kinds of batteries can be badly damaged, and their useful lives shortened, by having too much of their stored energy expended between infrequent charging cycles.

Buy a true deep cycle battery (such as a Concord brand) whether it's a conventional lead-acid or an absorbed glass mat (AGM) one. Most 6 volt golf cart batteries are deep cycle batteries; some TM owners have chosen to double up on them in place of a single 12 volt battery. You'll wind up paying more money initially for a deep cycle battery. Also you'll have a heavier battery but it will have a longer life and give you much less trouble in the long run.

Sorry, Paul H., for another of my long-winded explanations.  ;D ;D

Check out this site for more information. this should help.



http://www.windsun.com/Batteries/Bat...le%20batteries

Gregg

[Bill]

Jim -

With the 2720SL, it would be difficult (not impossible, but difficult) to mount batteries on the tongue.  The propane tanks and spring bar brackets get in the way.  If you have a swing tongue, that makes it even harder.  Still not impossible, but I suspect you will end up putting the second battery in the rear compartment, with the first.

TM did a really chintzy job of mounting the battery box back there.  They just chopped out a hunk of the upper skin, removed the foam below it, and dropped the battery box into the hole, so the entire weight of the battery rests on the lower skin. The skin is kinda thin aluminum sheet, so this seems to be less than a stellar approach.

There was a thread last July (search on the terms "battery box skin&quot about rebuilding the battery box so the weight will rest on the upper skin (the floor) rather than the lower.  I would suggest that you do this, especially if the new battery is larger/heavier than the original.  I would also suggest that if you add a second battery, you mount it at the other end of the compartment, to spread the weight out.

Other than that, it sounds like a great idea.  I plan to do this when my OEM battery dies.

Bill

Wow Bill, on my 1986 3023, (Battery located under the couch), it sits in a box that is placed in the hole resting on the *top* skin, did they change that design I wonder?

[glow=red,2,300]Happytrails.........[/glow]

On my 3023 the battery sits right behind the propane tanks.  This must be a new design for 2003.

I added a 2nd 12 volt battery right behind the LP tanks next to the one already installed on our 3023. Tried a 6 volt, but the added height hits the bottom of the front roof section when closing when you use a battery box. It would work without a box. I would still like 2 6-volt batteries over the current 2 12-volt batteries. When it's time to replace them, the battery bracket can be cut and lowered about an inch to accomodate the needed height. This summer will be our "capacity" test for the 12 volt batteries and if I'm not satisfied then I may upgrade sooner.

Wade