The battery brochure for this battery can be found here...
http://www.mkbattery.com/images/ss.pdf
It implies that float charging can keep these batteries going for a while. With IRI we end up charging batteries during the summer for practice. Then we don't really start using them for several months and do not leave them on float. Over the years, we have not noticed any serious deterioration. We use a CBA-II from West Mountain Radio to track batteries and compare them from one year to another. We have generally been getting usable service life for practice of three years or more.