Which Deep Cycle Battery?

[boltos]

I have checked my reprinted Service Manual and the original Owner's Manual for a spec on the battery...to no avail. I have a '72 23ft Safari, and just bought a '71 21ft Globetrotter...it came with no battery.
I went to Sam 's Club to buy one and thought I better find out more. I could duplicate the one that's in the Safari..but I really don't know if it's the specified...so, what kinda spec can anyone volunteer that could help clarify what deep cycle batter I need?

Thanks in advance,

[stephen.s1]

Buy the biggest, heaviest one that'll fit into the space available.

[Kistler]

I forget where I read that Interstate SRM-27's, which I have, are not truly deep cycle.. ??? came with the thing in 2002.

What should I buy? I am with sorehead however, don't have unlimited money, but my wife get's Social Security

Kistler

[Pick]

Trojan makes some really good deep cycle batteries. It is the brand most often used in golf carts, floor sweepers, etc.Trojan

[Creampuff]

Costco sells 2 sizes of marine deep cycle. I'm currently running the largest of the 2 which fits fine in my '67 Safari. I have used the smaller one with good success as well but decided to go bigger for the 3 day boondocking specials.

[RoadKingMoe]

The Interstate SRM-27s that came in our '01 are pretty sulfated up by now. I never did like it that they were only 85AH, compared to what some of the Trojans provide.

But I've discovered I like battery maintenance even less, so these are going to be replaced with the largest (Group 31 if possible, Group 27 if not), Lifeline AGM deep-cycle batteries I can fit in the compartments. I'll sacrifice some amp-hours for the low maintenance and low self discharge.

Here's the Lifeline Distributor Finder

[silverback]

Originally Posted by RoadKingMoe

But I've discovered I like battery maintenance even less, so these are going to be replaced with the largest (Group 31 if possible, Group 27 if not), Lifeline AGM deep-cycle batteries I can fit in the compartments.

Maurice, These look great, but my rough weight calculation comes in at around 138 lbs for a pair of the group 31s. I haven't weighed my current battery set, but I'm betting they are less. So upgrading the batteries would also affect tongue weight. Or am I being a nit picker?

Ken

[71_safari]

Originally Posted by silverback

Maurice, These look great, but my rough weight calculation comes in at around 138 lbs for a pair of the group 31s. I haven't weighed my current battery set, but I'm betting they are less. So upgrading the batteries would also affect tongue weight. Or am I being a nit picker?

Ken

Yes, it affects the tongue weight, but it may go up or down, depending on where your battery is located. On many early 70's, such as my 71 Safari, the battery is actually in the rear curbside. I would love a couple of AGM's when my group 27 lead-acid goes, although I may settle for one so as not to add weight overall.

[uwe]

I can't get to my trailer right now to read the battery label, but our 71 tradewind came 3 yrs ago with an Interstate RV battery. The battery lives under the rear goucho, and is completely sealed and maintenance free. It has served us very well, despite the low amp hours. It's never gone dead, and it never left us without lights, even before we got the generator. Plus, we use it with the original Univolt, which receives mixed reviews here on the forums.
I can recommend the Interstate product whole-heartedly.

[Kistler]

Thank you, Maurice, for the info on Lifeline batteries; I guess I'll have to see what the GPL - 27T ones cost. Apparently they are available at the local Batterys Plus here in Tucson.

They apparently will raise my tongue weight about 25 lbs. I think my Interstate SRM-27s weigh about 50 lbs each.

I think I'll wait until March to buy batteries, however. We are not going anywhere except for a little jaunt in February to Las Vegas and will have full hook-ups. One of the SRM's has a reading of 520 and one 470 so I guess they's do for reststop pump running.

Kistler

[silverback]

On our CCD the two Interstates are in a compartment just behind the propane tanks on the tongue. Kistler, thanks for doing the weighing (I'm sure yours are pretty close to mine) and the shopping research. It looks like we have Batteries Plus in Phoenix also.
Ken

[Kistler]

de nada....it was Maurice that did it.....thank you again Maurice!

I am a little worried about the size...the SRM-27s are about 6.5 in wide X 8 high X 12 deep.

The Lifeline GPL-27Ts are 12.9 in deep X 9.25 in high X 6.6 in wide.....I figure the deep has play and the plastic tray can surely handle .1 inch wider but the height but the 1.25 inch taller high maybe a problem????? My trailer is not home here so I can't measure the door opening/compartment size right now.

Kistler

[RoadKingMoe]

Sorry guys... been off-line for a day or so. Yes, it would be a bit more tongue weight, but not much. I too am unsure about the Group 31 size. It would be so close that the only way I'd feel good about it would be actually cabling one up and trying to stuff it in there.

[RoadKingMoe]

One other thing... AGMs can take a bit more voltage in the bulk mode, and need less voltage in the float mode. Ideally, one would upgrade the converter to something like the Inteli-Power with Charge Wizard, rather than keep the 13.8V single-stage Magnatek.

[Kistler]

Wow, another good idea for a Christmas gift for Brenda

[overlander63]

If you have a chance, look at the amp/hour ratings of a high cranking amp 27, and a low rated one. The lower cranking amp rated one usually has a higher amp-hour rating, and it also contains more fluid by volume, so takes longer to boil dry, if that is a problem with your trailer. Also, the lower-rated one tends to have slightly more space between the plates, and therefore, less chance of the plates contacting each other. The lower amp batteries may also last longer, because as the battery is charged and discharged, small amounts of plate material tends to slough off and fall to the bottom of the battery. This can build up until the material from plate "A" touches the material from plate "B", creating a short, or a bad cell. The further the plates are from each other, the longer this will take, all other things being equal.
Terry

[silverback]

Does anybody know what batteries come with the factory Boondocker package? These are decribed as glassmat (AKA AGM) batteries. I wonder if they use any of the Lifeline models we were discussing earlier? That would help decide which of those would fit. Terry, if my understanding is correct the AGM batteries eliminate the boil dry problem.
Ken

[RoadKingMoe]

I wouldn't be surprised if they are the Optima brand AGM batteries, the most popular and widely known AGMs. These have spiral-wrapped cells, that are alleged to be more rugged than more traditional AGM designs. The problem is that the spiral-wrap design, which looks like a 6-pack, makes poor use of the Length X Width X Height. There's a lot of wasted air between the round cells So they have less lead and less capacity than a traditional design. You can see this comparing their Group 31 specs with the Lifelines or other AGMs. Worse yet, their Group 34 size, while having the same base dimensions as a Group 24, is shorter, meaning even less capacity. So they're best left to high-shock environments where amp-hours aren't as much of an issue. Another area in which they excel are in high cold-cranking amps. So they're better for starting big, high-compression, or high-pressure injection, engines.

[the ponz]

I was told that the batteries installed in golf carts, and the like, are of a more heavy duty type than the standard deep cycle battery.

[Mike76251]

Optima yellow top hands down.
I have 10 of the things installed in various things (all 10 years old).