We have 2 six volt house batteries on our MH. Does this make ours a group 12? We have seen group 24 in Wallie World and wondered what it meant--is it 2 12 volts or the weight or what?

Battery size doesn't add a group 12 will always just be a group twelve.

Adding comes in when looking at amps, volts and watts only.

I also wondered about the reason behind this battery naming convention. You got Group 24, Group 27 and I think Group 31 too.

"Group size
A set of standard sizes for the external dimensions of a battery, standardized by BCI. All "group 27", etc, batteries are the same size, though they may differ in weight and capacity. We have a chart of the group sizes most likely to be found in a car. "

Group ## to dimension chart:

http://www.rtpnet.org/~teaa/bcigroup.html

BCI site:

http://www.batterycouncil.org/

I thought that maybe the Group number naming conventions were related to the sum of the external dimensions, like measuring/adding box dimensions for USPS mailing.

But they don't seem to add up. Just wondering why they decided to name them by these Group numbers...

Interesting to learn that the group number is only about external size dimensions and not about storage capacity or weight.

quote:

Originally posted by Stanley P. Miller:
"Group size
A set of standard sizes for the external dimensions of a battery, standardized by BCI. All "group 27", etc, batteries are the same size, though they may differ in weight and capacity. We have a chart of the group sizes most likely to be found in a car. "

Group ## to dimension chart:

http://www.rtpnet.org/~teaa/bcigroup.html

BCI site:

http://www.batterycouncil.org/