is a good site that tells about the Optima battery and while it has some things I think are hype most seems to be valid. The Optima is not a gel cell but uses some thicker than normal but thiner than gel cells sulferic acid. There is little tech info just average consumer stuff. You can use that site to choose the correct Optima for your use.
The site claims Optima's are deep cycle and starter cycle batteries. Deep cycle batteries don't work well for heavy discharge and starter cycle batteries don't work well for deep cycle discharges. So they have struck a happy medium. They have red, blue and yellow top batteries, the reds are for starter cycle, the yellows are for start/deep cycle, and the blues are for deep cycles. They say you can use them interchangeably with certain reservations.
Read the site.
I will see if I can find a site that gives tech info on the Optima.
Still trying to contact #1 son to ask about lead acid Exide batteries specs. I'd still like to see an inhouse study by Exide or another company compairing them to several brands. I'm sure it's been done to see how their product stands in comparison.
#2 son with the modified 914 lives in Lou. and #1 son lives in Tenn. He don't work for Exide anymore, he works for a company that wires and outfits helicopers.