I'm shopping for batteries for my new TT and could use some advice on AGM vs 6 volt flooded golf cart batteries. I used the latter on both of my previous RVs and my first thought was to get the same now. However, it does seem AGM batteries have several advantages. Some specific questions about AGMs:I've read that with AGM batteries there is no advantage of having two 6 volt ones, unlike the advantages of two 6 volt wet deep cycle batteries. Is this correct? If so, does that mean that one 12 Volt AGM would serve as well as two 6 volts, or would two 12 volts be needed for equivalent performance?I've also read that AGMs have very specific requirements regarding how they are charged. Does the typical battery charging system in RVs work satisfactorily with AGM batteries?Amazon has an Amstron AGM 6 volt, 210 Ah golf cart battery for $210 and a VMax 6 volt AGM deep cycle 225 Ah for $260. I've never heard of either brand. Does anyone have any experience with either? Any other brand suggestions (cost is a factor but not at the expense of poor quality and performance)?Any general comments about AGMs vs flooded deep cell batteries would also be much appreciated. Thanks for any help.Mike

What advantages are you looking for to be worth spending double the money?No maintenance and fast charging are the primary advantages. Do you spend time off grid?What make and model converter do you have?Any issues to avoid the wet cell golf batteries?

It is unlikely that any one 12V battery (AGM or otherwise) will have the capacity of two 6V golf cart batteries. Check the amp-hour ratings to compare.

Do you "need" spill proof type battery like AGM?To me if you are looking for the most Ahr for your money those AGMS are extremely expensive.You can get Sams GC2 FLA batts with 210Ahr for $80 per 6V battery vs $210 (plus $32 shipping) per Amstron 210 Ahr 6V battery.Sams 6V FLA costs $.38 per Ahr and Amstron is $2.42 per Ahr.Something else to consider, there are several types of AGM, one is only good for 80% or less DOD (Depth of Discharge) and the other is good for 50%-60% DOD.Compare that to Sams FLA GC2 which can be easily discharged down to 20% DOD without harm (although at somewhat expense of some of the life).FLA can also be discharged 100% and as long as you recharge as soon as possible it will "recover" to some sort of usable capacity.AGMs if discharged to 100% will result in expensive door stops (even if recharged immediately)Granted AGMs are considered Maintenance free, that same characteristic can also be a downfall in the fact that if you overcharge a AGM it will vent the pressure and when that happens you lose electrolyte and can not add new electrolyte.With a FLA if you overcharge it you can at least add water to it..There are a lot of pros and cons to both types..To me, watering my batteries is not a chore, I do it once a year and only takes 10 minutes at the max. So far no corroded terminals but I use a product called No-Alox which is a grease used for connection aluminum wire to copper wire.. It stops oxygen and moisture from getting to the connection and hence prevents corrosion. Been using that for years on my vehicle batteries with success..You just need to ask yourself if you just simply want (and don't mind paying for)the "cool factor" when you tell folks you have AGMs.

You need a smart three stage charger where you can turn off any equalization functions. Same applies to any solar charging systems. AGM do not like being charged at 15+ volts.At the rate my original 6V were rusting the battery area they would be dragging on the ground by now if I had not switched to AGM. You need to do a lot of off the grid camping to justify the extra cost IMHO.

I love the cleanliness. Just dust them now and then!AGM v flooded 2011

AGM Battery Questions | Good Sam Community

25 Replies

Denny___Jami
Explorer
Nov 12, 2014
mena661 wrote:
Denny & Jami wrote:

Your right my 03 Optima D31M batteries have 55AH the new D31M have 75AH

Denny
What is the weight on the old versus the new? If they're even remotely the same weight, the new is a MUCH lower quality battery.

I don't know about the weight but it's taller than the ones I have with about the same base foot print. How good they are I won't find out until one of mine dies.

Denny
MEXICOWANDERER
Explorer
Nov 11, 2014
I knew things were bad when I last chatted with the president of Battery Council International in 1994. He was obsessed with "recylalbility" I brought up the subject of specifications, he rattled on about ease of lid removal to get at the plates, I spoke of decreasing antimony content, he babbled about recovery of sulfuric acid percentages. I wanted consumer protection in the form of industry standards that were to be made mandatory - he gibbered on and on, sounding like an aluminum beer can recycle recovery lab. Finally I got fed up: "If you want excitement in plate additives try depleted uranium".

There was dead silence. "Oh great!" he moaned "We are trying to standardize recovery issues and you want to throw radioactivity into the mix".

Some people just cannot take a joke. The manufacturer I was representing, had turned white as a sheet.

That's when I realized the bulk of the industry had just lost touch with planet earth.

Instead of acting like idiots, the BCI should be focusing on establishing a Pb purification mill in the deserted wasteland of northern Mexico. Shooting for a figure of 99.99% purity. That's about as likely as convincing US and State government agencies that a key to economic booming is hinged on affordable energy prices.
mena661
Explorer
Nov 11, 2014
Denny & Jami wrote:

Your right my 03 Optima D31M batteries have 55AH the new D31M have 75AH

Denny
What is the weight on the old versus the new? If they're even remotely the same weight, the new is a MUCH lower quality battery.
Denny___Jami
Explorer
Nov 11, 2014
MEXICOWANDERER wrote:

"Old Timers" who report success with many years of good service have to remember this is not 2005, or whatever. The quality of batteries has degraded. The Optima battery of 2000 is not the Optima battery of 2014. Keep this in mind for ALL batteries, flooded or VRB.

Grrrr....

Your right my 03 Optima D31M batteries have 55AH the new D31M have 75AH

Denny
BFL13
Explorer II
Nov 11, 2014
I have four 6s. All bought in 2011, six months apart in age. Two Interstate GC2 XHD 232AH and two Exide GC135s at 226AH I use them in one bank series-parallel.

Each set is still at baseline SG after four "seasons"and seems to be at full rated capacity using Trimetric AH information.
MEXICOWANDERER
Explorer
Nov 11, 2014
You are LESS likely to end up with onion-skin thick plates if you choose golf car batteries. Note the word, less.

Compare brands, the heavier the battery AND AND AND not gaining ampere hour capacity in relationship to the difference in weight is a clue that the battery has heavier plates which you want. Many so-called deep cycle AGM batteries have .060" thick plates - that is a cruel joke.

"Old Timers" who report success with many years of good service have to remember this is not 2005, or whatever. The quality of batteries has degraded. The Optima battery of 2000 is not the Optima battery of 2014. Keep this in mind for ALL batteries, flooded or VRB.

Manufacturers who refuse to divulge plate thickness are crooks, plain and simple. There is not a reason on the face of the earth to with hold basic battery specifications, Plate paste compounding, grid alloys and other information is eligible for proprietary secrecy - not positive plate thickness. And I do not give a damn which company decides to slimeball withhold plate thickness - it is as bad as a sign as a taxi driver who refuses to tell a patron how much a ride is going to cost until they arrive. The federal trade commission is a joke, and should be dissolved and executives fired.

Grrrr....
beemerphile1
Explorer
Nov 11, 2014
Sam's Club Duracell GC2 at $85 each for 215ah.
time2roll
Nomad
Nov 11, 2014
Some Costco and some Sam's Club have 208 to 232 rated GC2 wet cell for about $100.
These have a very good following.

If you are going to pay $150 I would take Trojan T105 over the Interstate.
liketoride2
Explorer
Nov 11, 2014
Thanks to everyone who replied for your advice and information. There are obviously lots of pros and cons between the two types of batteries. We do spend a lot of time off the grid so that is one factor not present for many RVers. But, when I started shopping I was under the misimpression that AGMs were lighter, obviously not so.

My first thinking was to buy two Interstate 6V golf cart batteries, having had good experience with those in the past, and, after digesting all the info posted here, I'm again leaning in that direction. At about $150 apiece the difference in price isn't half that of AGMs, but significant. If anyone can suggest a lower price alternative, equivalent in quality to the Interstates, please do so. I have the idea, possibly wrong, that they should be above 200 Ah (20) rated.

I don't even have possession of the new TT yet so still have some time before making a final decision.

Thanks again to all of you, I really do appreciate this.

Mike
Denny___Jami
Explorer
Nov 11, 2014
I installed 2 Optima Blue Tops 11.5 years ago and they show no signs giving up never had to clean anything except for some dust off the top. I've never measured my draw but when dry camping they they seem to last about the same amount of time. Take them for granted anymore and never look at them.

Denny