>Interstate Group 27 (13" long) battery has a Reserve Capacity rating of 160
>minutes. This is the battery used by Airstream for about the last 5 years When

I just measured the battery I took out of my Airstream for the winter. It is 12" long. Would this still be considered a Group 27 battery? I have had the trailer since May '97. It was built in 1989. Even though this battery when I took possession of the trailer looked well used corroded, but cleanable terminals), it could not possibly be the original battery.

I guess what I'd like to know is whether 12" batteries have the same capacities as 13" batteries?  Maybe when this battery gives up the ghost, I should get as long a battery that will fit in my battery compartment. I'd appreciate being enlightened, otherwise I'll end up getting sold something that may not be in my best interests.

Reserve capacity challenged,

Pete