At the offseason events 1885 attended in the last two weeks, we struggled to maintain proper charge on some of our batteries. I'm not sure who/what/why or even how we got the batteries we have, but they're a mixed bag of some of the FRC legal batteries from 2014.
Problem is, not all of the brand new batteries hold proper charge for an entire match. The Sigma battery had the worst "life" - as in, it would start at 13.5V and always come back at < 10V according to the Battery Beak.
I found a comparison of specs for batteries related to the FRC-legal batteries, which led me to the fact that I don't know which specs actually matter for our use case:
http://www.atbatt.com/sealed-lead-ac...s-12180-nb.asp
Which FRC-legal models (other than the Enersys) worked well for teams this past year?