6/12V house batteries

[nightwatch]

Sorry for the newbie question... but.
My SeaBreeze has two 6volt house batteries in series. I am considering replacing them with two 12volts in parallel. Wait!!!, I DO understand that two 12's in parallel should deliver same VOLTAGE as two 6v's in Series. Is this alright in most situations? Is there something I am missing, or is this a reasonable idea?

[GaryKD]

Hi nightwatch,
Welcome to iRV2. You are correct. The reason RV owners usually use 6 VDC deep cycle batteries is that the plates in the 6 VDC batteries are thicker and will last longer.

Take a look at the battery capacity (AMPS) and purchase the battery(s) that meet your needs. Because both configurations deliver 12 VDC, focus on the AMPS delivered over how many minutes. This information should be in the battery spec sheet.

[Harry B]

You'll probably find that 6 volt deep cycle batteries are priced more reasonably than 12V deep cycle batteries.

[RV Wizard]

Also 6 volt batteries are more durable do to the size of the cells and construction of the plates. I got 9 years out of my last set of 6 volt golf cart series batteries.
Here are some links to research batteries:
U.S.Battery/Leader in Deep Cycle Batteries
Frequently Asked Questions (FAQ) - DC Battery Specialists
Deep Cycle Battery FAQ
http://www.rvsolarelectric.com/sources.htm
Car and Deep Cycle Battery FAQ, Battery Manufacturers and Brand Names List, and

[wa8yxm]

There is quite an argument on 6v v/s 12 v but I will give you the bottom line.. COST
If you get six volt batteries at Sam's Club the price is hard to beat.

Now, some facts:
Two six volt GC-2 size (IE: Interstate U-2200, US US-2200, Trojan T-105) 220 amp hours

One Group 24, about 75
One group 27 around 90-95
One group 29 Around 100-110
One Group 31 around 125

So unless you go with Group 31's which normally sell for around 100 plus each, you will loose capacity, v/s less than 70 for the GC2's at Sam's.

I found a link (And posted it) yesterday that suggested some additional value to the GC-2 Six volt pairs too but ... in truth... That's what the argument is about. I happen to be of the school that feels True Deep cycle batteries are better for House Battery than teh Marine/Deep cycle types (longer overall life, same capacity (that is hours between recharge) but longer over all life (years before replacement)