New Coach Batteries

[Bionic_Man]

It is about time to change batteries in the coach. I have the standard two 12-volt system, which I think I will stay with. But I am considering going to AGM batteries.

When we camp, we usually have electricity. At least until fall when we put the boat away, and then we switch to more federal lands in the mountains without electricity. The RV is stored at home, and is left plugged in so that we don't have to load/unload the fridge every trip. I do my best to add water to the batteries over the course of the year, but sometimes I forget.

Would there be an advantage to going to AGM batteries in the above scenario?

[3_tons]

pianotuna wrote:
Hi 2oldman,

A role in WKRP in Cincinnati. He was the advertising sales manager. One of his fund raising efforts involved throwing turkeys out of a plane. He genuinely thought turkeys could fly.

2oldman wrote:
Who is Herb Tarlek?

I’m afraid he’s now hold up with John Galt...Others soon to follow...

[pianotuna]

Hi BFL13,

It is my understanding that 'normal' AGM cells are a "starved acid" design. So once all the electrolyte has been moved to the plates, charging more won't cause the battery to gas.

Telcom jars are a surplus acid format--so best to not push the charging rate, or they may gas.

Of course, all lead acid formulas are subject to positive plate shedding. Once those plates erode there is permanent loss of capacity. In the case of flooded jars, the space beneath the plates may fill up and eventually may short them out. That is what happened to my Marine jars after nine years. One of the seven became a vampire. I was able to save the larger bank because of having a disconnect switch.

The other failure mode is dendrite growth. When they penetrate the plate separators, it is game over, and a catastrophic failure, with lots of heat and gassing.

Dendrites are a problem for LI batteries, too.

BFL13 wrote:
"The battery with the LEAST sensitivity is an AGM. They recharge until the electrics run into a stone wall then refuse to charge more."

The thing there is that if you keep the charger on, the AGM will not charge more, but instead the amps go back up and so does battery temperature.

With Wets, if you do that, all that happens is it gives off more fumes and you can replace the lost "water".

To me, that makes the AGMs more sensitive to recharging when you aren't right there when they get to "full".

[pianotuna]

Hi Mex,

I'm going to guess that the one exception is Lifeline. (other than Surrette)

[pianotuna]

Hi 2oldman,

A role in WKRP in Cincinnati. He was the advertising sales manager. One of his fund raising efforts involved throwing turkeys out of a plane. He genuinely thought turkeys could fly.

2oldman wrote:
Who is Herb Tarlek?

[camperdave]

nvm

[2oldman]

MEXICOWANDERER wrote:
I tried bringing some light to this on this forum for what? Sixteen years?

Clearer and more concise writing would help. Who is Herb Tarlek?

[pianotuna]

Perhaps for you that is true. For me it is NOT true at all.

azdryheat wrote:
6 volt golf cart batteries are the way to go.

[BFL13]

"The battery with the LEAST sensitivity is an AGM. They recharge until the electrics run into a stone wall then refuse to charge more."

The thing there is that if you keep the charger on, the AGM will not charge more, but instead the amps go back up and so does battery temperature.

With Wets, if you do that, all that happens is it gives off more fumes and you can replace the lost "water".

To me, that makes the AGMs more sensitive to recharging when you aren't right there when they get to "full".

[MEXICOWANDERER]

EVERYONE
READ THIS LOUD AND READ IT CLEAR


There is but one single solitary manufacturer of car jar size true deep cycle batteries in north America.

Rolls & Surrette

Not Trojan, not Exide, not Johnson Controls, not Deka, not GNB

but Rolls

And put a period behind it.

Regular and I mean REGULAR ORDINARY DAY IN AND DAY OUT car starting batteries of the 1960's and 1970's were just as cyclable as today's DEEEEEEEEEEP CYCLE RV batteries.

Yes separators have changed and through the cell wall interconnectors are different but the notion 6-cell batteries of today are different is a cruel marketing hoax.

Don't get me wrong. Car starting batteries do have THINNER and more porous plate paste.

In the 1970's it took a 150 pound 8-D battery to achieve 1,000 CCA.
Today my junior olympics size group 34 brags it offers 825 CCA This turd is half the size of a group 65 battery which has similarly thin porous plates

There are golf car batteries of which the better brands are built to do cyclable duty but they exhibit 475 CCA. Is it a miracle? No, it is a giant Federal Trade Commission Free CON JOB.

AGM is not free of Herb Tarlek grade BS. Those AGM batteries offer a ton of battery with .045" plates have just that, forty five thousandths thick plates and there is only one exception to this. That exception has plates in excess of a tenth of an inch thick.

But ignorance rules. Batteries are not insensitive. They need EXACTING care and 99% of buyers could care less about exacting care. The battery with the LEAST sensitivity is an AGM. They recharge until the electrics run into a stone wall then refuse to charge more. This rant is not a battery manual so if you want more info Rolls & Surrette and Concorde provide excellent ones free to download.

Self titled opinionated users come up with some of the most outrageous claims that defy common sense and automatically leads to their degree of truthfulness and even their perception of reality.

I tried bringing some light to this on this forum for what? Sixteen years?

And still, I read nonsense posts reinforced with agreement from similarly ignorant (they refuse to read Instructions or click on free legitimate information from two of the finest battery manufacturers on the face of the earth. But they take it online and preach the gospel about batteries.

THE QUEST is to find the LEAST OFFENSIVE CONVERTERS AND CHARGERS that will allow these batteries to lose the LEAST amount of capacity and deliver the maximum amount of lifespan.

A simple power supply like a Meanwell or Megawatt would DOUBLE or TRIPLE the life of an AGM battery but interest in how to do it is about on par with adopting a red-headed stepchild.

Yep bet your butt I'm disgusted and I'm frustrated today.

If they refused to discuss it publically then fine I have no qualms about that.

[azdryheat]

6 volt golf cart batteries are the way to go.

[Lwiddis]

A good solar system with adequate amp hour capacity batteries would eliminate keeping the unit plugged in at home and mostly eliminate generator use when dry camping.

[pianotuna]

Hi Mex,

I guess I was up too early to comprehend what the OP said. Ty for pointing that out to me.

I prefer AGM. I prefer used Telcom jars as they don't cost an arm and a leg and the life of your first born son.

Proper charging is important, that statement applies to ALL battery types.

I will never place a "house" battery in the living quarters. It is a fine idea, until there is a failure. Then it quickly becomes a lousy idea. H2SO4 is not just an unpleasant smell.

There is nothing like not having to lay down in the snow to check electrolyte levels.

[ajriding]

Depends on what your boondocking is like. Do you boondock for long? Just a weekend or for weeks on end?
If just for the weekend maybe just stick with the cheap Marine battery. Fill with distilled water, never tap.
Do you have any solar?

For the campground phase of your camping experience then a small exit sign 12v battery would be enough to get you past the drive portion, you don't need hardly any battery, so then now you are just getting battery for that Fall when you boondock.

Boondocking in the fall when it gets cold means running the furnace? The furnace fan is a power hog, so after one night you will need more power than the battery has left. You need a big battery bank (two batteries) or a way to top off the one battery. Solar works perfect, but some ppl use generators for a few hours to charge back.

[MEXICOWANDERER]

"and then we switch to more federal lands in the mountains without electricity."

Federal land has current bushes PT ? 🙂


Purchase a true deep-cycle AGM battery and the differences really multiply especially if you have an inverter. If your converter is a Wifco, upgrade it.

[2oldman]

I loved my AGMs. Occasional dusting was the only maintenance.