Wet cell vs. AGM batteries

[dog walker]

I have to replace my house batteries(after 5 years). Currently have four Interstate U2200 6 volts. I'm looking for advice re simply replacing the U2200's versus switching to two 12 volt AGM type. I like the idea of not needing to monitor/add water periodically. I also can't access constant battery float charging while in storage. I don't know if the AGMs would give me the same "run time". I believe they would cost more. Thanks.
George

[RickO]

Hi and welcome to the forum.

I believe AGM can certainly perform at least as well as your wet cells. They'll stay much cleaner and you won't have to maintain the water levels... but they are considerable more expensive.

When having my alternator replaced by a Freightliner Oasis dealer last year, they had to replace a chassis battery and only had an AGM in my size. It's worked just fine and has been trouble and maintenance free.

Rick

[Gary RVRoamer]

You will need at least 4 AGM 12v to provide the same amount of amp-hours as your 4 wet cell 6v's. Two won't come anywhere near close.

4 x Group 27 size 12v's would yield about 420 AH. 4 x Group 31 size 12v's yields about 460 AH, a bit more than the 440 you have with the 6v's.

The AGMs will cost about 3x as much as the 6v golf cart batteries but they are maintenance free.

[B Bob]

I have AGM. I was told the charging of them is a bit different than standard batteries. So keep that in mind if you switch.

[Wolfpack Fan]

Here's a good article that compares the merrits of flooded, AGM and Gel batteries. Should provide usefull info for you.

Battery Types: Flooded versus AGM and Gel

[Ed-Sommers]

I know what you mean! I just detest spending that 10 or 15 minutes (in my case) checking, cleaning, and watering, my 8 batteries each month.


Ed

[dog walker]

Thanks for the response. Gary gave me what I was looking for. I was under the false impression that two 12 volt AGMs would give me the equivalent amp hours. Buying four 12 volt AGMs is far too costly and I don't have the space.

This forum is awesome!
George

[az bound]

Originally Posted by Gary RVRoamer

You will need at least 4 AGM 12v to provide the same amount of amp-hours as your 4 wet cell 6v's. Two won't come anywhere near close.

4 x Group 27 size 12v's would yield about 420 AH. 4 x Group 31 size 12v's yields about 460 AH, a bit more than the 440 you have with the 6v's.

The AGMs will cost about 3x as much as the 6v golf cart batteries but they are maintenance free.

That is not necessarily so. I have 2 -12 volt AGMs, 245 AH each for a total of 490 AH. It all depends on what you buy and what there is room for.

[wa8yxm]

In doing a lot of research I find there are 3 kinds of batteries you should consider

Flooded wet cells, which you have, are the lowest cost, the six volt GC-2 size battery is the most produced lead acid battery in the US and thus the unit cost is lowest. Golf Courses buy these by the small truck load. Every year. They give you the most "Bang for your buck" epically if you buy at someplace like Sam's club. They also have the longest "Design life" of all three types I will discuss here.

Maintenace free (Wet cell type) have the advantages you desire of not needing to water them or clean them as often They cost a bit more than the above, and do not last quite as long, but for what you want a good maintence free DEEP CYCLE (NOT marine/deep cycle) might be a good choice.. Trolling motor batteires from Wally world?


AGM: The most costly, and the shortest lived of all the batteries I will type about (Source on life is battery company web pages, "Life in terms of recharge cycles) These do have the advantage of not haveing a "This side up" and can, it seems, take a slightly faster charge or discharge.. Provided you have a converter big enough to charge them faster.

OPTIMA is not another type, it is AGM, shaped differently, Still higher cost, and only 60% the capacity, per their web site. The worst "Bang for your buck" in the store.

[Mr_D]

After almost 10 years I had to replace our Interstate U-2200 house batteies. I used the same ones again due to the life span of the originals.

[ARTWERKE]

If you do let water level get low, or leave a light on by accident. 6V golf cart batteries are much more forgiving than the others. Art.

[jauguston]

If you have a properly operating three stage smart converter frequent battery water adding is a thing of the past. My last coach had 4-6v interstate U-2200's and a PD 9160 converter with a wizard. It was plugged in 24-7 and I added a small amount of water ONCE a year. The best bang for the buck for house batteries is still flooded lead acid golf cart type 6v batteries. The very worst are Optima.

Jim

[Gary RVRoamer]

If you want AGMs, replace your flooded cell 6v's with AGM 6v's. Both Trojan and Lifeline/Concord make 6v golf cart batteries with AGM technology. Still costs an arm and a leg, though.

[Gary RVRoamer]

I have 2 -12 volt AGMs, 245 AH each for a total of 490 AH. It all depends on what you buy and what there is room for.

True enough. I was intentionally ignoring the huge 8D size 12v's, but they would have the necessary AH.