6v, 12v, battery groups...

[rjmotyl]

I've seen posts about 6v and 12v batteries, what are the pluses and minuses of choosing one over the other? Also what should we look for in the different types of batteries (group, etc.)? Any reference sites?

[Murff]

Personally, I use two 6 volt golf cart batteries. Bigger capacity than two 12 volt batteries of the same size. I admit I am not the best person to explain the technically aspect of it, so I will let someone else weigh in.

Murff

[Subaru297]

The most common rv batteries are:

12volt batteries
Group 24 -- 65 to 80 Amp hours
Group 27 -- 80 to 120 Ah
Group 31 -- 100 to 130 Ah

6volt
GC2 (Golf cart) -- 220 Ah
L16 -- 400 Ah Not a very common rv battery (too large)

The group refers to the size of the battery.

Two group 27 in parallel will give you similar capacity as two GC2 batteries in series but the advantage of the GC2 is they are usually more robust and will handle more cycles and maybe slightly deeper discharge. They are "true" deep cycle batteries.

I could be making all that up and I think there are arguments to made for both. The differences might not be apparent without pushing the batteries capacities and cycles and getting the most life out of them.

Cheers

[RoyBraddy]

I always like to look at the specs on how long the battery will produce 25AMPS DC current i.e. This is explained in the AH rating numbers but means more to me to see how many minutes the batteries will operate...

The large core size in the Golf Cart batteries really stand out in this respect... Since the Golf Cart batteries are in big demand you get a pretty good price break too...

[SkyBound]

Keep in mind that the AmpHour rating is the total discharge power available. Since you don't ever want to drain your batteries completely, your effective usable power is less. Most recommend never to exceed 50% discharge, so you have half of the rated AmpHours usable.

[Mustang65]

Originally Posted by rjmotyl

I've seen posts about 6v and 12v batteries, what are the pluses and minuses of choosing one over the other? Also what should we look for in the different types of batteries (group, etc.)? Any reference sites?

As I say most of the time when the discussion of batteries comes up, if you ask 10 people you will probably get 10 different reasons as to why they like 12 vs 6 volt batteries, true deep cycle vs hybrid, different mfr....

With new products coming on the market all the time the benefits between the 2 voltages (6 or 12) is shrinking. They have improved the 12 volt lines over the past few years and USBattery just released a new 145Ah 12Volt battery (no price yet). It used to be that the 12Volt deep cycle batteries lacked Ah unless you paid a ton of money... now they have started to drop in price. A benefit of a high Ah 12 volt battery is that it comes in one package and not 2. Some of the benefits people say is that if one of the 6 volt batteries goes bad, you do not have power. True, but I have yet to encounter a case where the battery just died, they usually do a slow death and it is noticeable (usually due to improper maintenance or age).

A lot of people think that they can just buy these expensive batteries and treat them like the inexpensive ones that come with the TT. You can, but most people do not perform proper maintenance on their batteries and start crying and moaning when they go south $$$$. I always recommend that people use the inexpensive batteries the first time around and get the learning curve out of the way, on inexpensive batteries...

I am still undecided as to what I will replace my existing 6 volt batteries with when they go in a few years (working on year 4 now). Already researching!!

For a little more battery information we have a "RVing with SOLAR" social group that has a little more information on the difference in batteries, just page down to the 2 part posts.

Good luck,

Don

[rjmotyl]

As usual, thank you all for the great info.