6v vs. 12v AGM deep cycle confusion

[Leland2]

I've read everything here and a number of other sites on this subject and I have a mental block understanding. I get different answers from different people too -- and still don't get it.

Here's my setup: I have an Alpenlite with 6 Interstate U2200 batteries, 1 100w solar panel, and a Xantrex Freedom inverter/converter . At 6 years, I'm thinking of replacing the Interstate's with AGM's.

In 6 years I've always had shore power and don't anticipate ever dry camping.

I know I"ll probably go with 2 12v or 2 6v deep cycle AGM batteries. I'm unclear as to why one set might be better than the other.

I'm not focusing on cost here or amp hours. Just enough battery power to maintain the coach -- I think I need batteries even though I am plugged into to shore power -- but don't know this for a fact.

Someone recommended the 4D size (210 amp hours?). Don't recall why now but anything wrong with the 24 or 27 sizes?

Think my Xantrex would work fine with the AGM battery setup but don't know for sure.

Anyone out there with a similar situation -- or advice for a simple setup here?

Thanks in advance.

[christopherglen]

What is the rating on your inverter? My 3kw inverter pulls ~300 amps at rated load, 600 at max surge. My 3 85 AH agm's will run the ac, but voltage sags, I get low voltage alarms when surging to start the second AC. If you plan on using your inverter, get enough battery to support it. If you only go from outlet to outlet then any 12v battery will work. The agm just eliminates all maintance until it dies.

[Shadow_Catcher]

I will second the single AGM don't have to be watering etc. We do boondock and I chose a 150AH Lifeline AGM for our teardrop trailer. You do not need that much but you do need some to power things when you are on the road or lose power and ya never know you may decide to stay in a campground i.e. State park with no 120V AC electricity.

[Me_Again]

Simplygib wrote:
I don't have a battery in my 5er. It's an old Alpenlite and works fine off the converter (on shore power all the time). Not sure but I don't believe this will work on newer rigs. Also, my rig never goes anywhere. If it did I'd need a battery to operate the disconnect switch.

The battery acts as a filter for the 12V supply, helping to protect the 12V DC electrical circuit cards in refer's, furnaces, stereos etc.

Plus it will give you some light in a power outage!

Chris

[Simplygib]

I don't have a battery in my 5er. It's an old Alpenlite and works fine off the converter (on shore power all the time). Not sure but I don't believe this will work on newer rigs. Also, my rig never goes anywhere. If it did I'd need a battery to operate the disconnect switch.

[45Ricochet]

Take two of these

and call me in the morning, errrrr in the year 2020 :B

[Veebyes]

I thought you were all set up & ready to go by now.

Amps is amps. Any of the battery manufacturer websites will explain it to you & give diagrams. Lifeline or Trojan, take your pick. Given the space that you have get 2 12V group 31s or, if you want to do some serious dry camping, get 2 4Ds.

2 12V group 27s will give about the same amp hours as 2 6V. The specs are all on the websites. 2X6V does not double your amps. It gives same amps but at 12V. 2X12V in parallel becomes 1 12V but double the amps of each battery.

[Me_Again]

Save your money on the AGM and install two Costco golf Cart batteries. Maintain well like you have with the existing batteries and they will last at least another 6 years.

Chris

[timmac]

I prefer two 12 volt AGM's just because of no maintenance, water here in the South West dry's out fast and always forget to add water, never have to worry about that with AGM type batts, besides I don't dry camp that much any more.

[Leland2]

2oldman wrote:

Leland2 wrote:
h 6 Interstate U2200 batteries, 1 100w solar panel, and a Xantrex Freedom inverter/converter .

In 6 years I've always had shore power and don't anticipate ever dry camping.

Your setup is quite the dichotomy..and I hope I've used that word correctly.

If you never dry camp you need only one battery, and it doesn't have to be anything humongous. I don't know why you have 6. That's way way overkill for you.

The solar and the inverter I would question too. Why do you have those things if you never dry camp?

Yes dichotomy is a good word. I wanted this equipment in place and got the bells and whistles when I custom ordered from Western.

It's just turned out this way. I dry camp with an '02 Lazy Daze that I ended up not selling after the Alpenlite purchase.

THANKS EVERYONE for clarifying some things. Going with a 12v AGM!

[KD4UPL]

The set up you currently have is for serious off grid usage. For your stated use of always plugging in it is completely useless.
I wouldn't spend the money or tote around the weight of big batteries if you're always going to plug in. The cheapest little group 24 or 27 would be fine for your needs.
AGM batteries are nice if you don't want to have to check the water or need to mount them in an interior space.
For your needs I would just use 1 12v battery.
6v batteries are the better choice for building a large battery bank that gets used hard. Yours will not.
6v batteries are typically build to be more robust than most 12v. They have a greater capacity for repeated deep discharge; something you won't be doing if you're always plugged in.
I build large battery banks for off grid homes. We generally use 6v batteries unless it's something really big and then we use 2v batteries. Standard design practice for off grid systems is to have no more than 2 or at the most 3 strings of batteries in parallel. You currently have 6 which is simply not a good design. It's very difficult for all the batteries to charge and discharge evenly.

[kopy_kat]

my last MH had 2 x Group 29 (1/4" longer than group 27, but much more amp capacity) but my new 5th wheel has 2 x 6 volt (the 2200 series) and I have had a solar panel for both set ups--

I really do see a lot longer amp draw-down with the 6 volt batteries--their lead plates are so much thicker, and golf cart batteries are designed for a long draw down and recharge whereas 12 volt batteries are not really designed for a long draw down period (this is from Interstate Battery company that sells both types pf batteries).

just my $.02 worth.

Larry

[2oldman]

Leland2 wrote:
h 6 Interstate U2200 batteries, 1 100w solar panel, and a Xantrex Freedom inverter/converter .

In 6 years I've always had shore power and don't anticipate ever dry camping.

Your setup is quite the dichotomy..and I hope I've used that word correctly.

If you never dry camp you need only one battery, and it doesn't have to be anything humongous. I don't know why you have 6. That's way way overkill for you.

The solar and the inverter I would question too. Why do you have those things if you never dry camp?