It's a good thing they date them, I'd never keep track. My combination deep cycle/starting battery was reading less than my other 2 grp27 in the house bank, but it seemed to be adequate voltage after resting.

But I could tell by the starting rpms, and how quickly they were fading, it was toast. It was dated Sep 06, so that's about 5 seasons, pretty typical in my experience. A new one was 100 bucks, that's up as is everything these days, especially if it's heavy.

The voltage difference between new house bank and the starting should have told me and I should have replaced it before launching. On the other hand, that was up a ladder, everything is downhill to the boat now.