Hey Scott, I deal with sales and service of UPS (uninterruptible power systems) for a living. All your AGM battery and charging-discharging figures make perfect sense. There is no substitute for the higher priced, quality AGM cells (I use the C+D Dynasty line). Boat batteries are notoriously neglected and rarely charged correctly. Here in Minnesota, where the boat battery business is mainly for trolling motors for fishing out of Lund boats, I often hear complaints about short battery longevity. Well, the main reason is the treatment they recieve. Solar panels should be considered a trickle charger, at best. I use a group 24 75ah, and a 18ah battery in the M23, and a 31ah (U-1) and a 7ah in the M17. All AGM style. I have an onboard charger using shore power at the slip for the M23, and a portable for the M17. Think spring, Bones ___________________________________________________________________ Speed up your surfing with Juno SpeedBand. Now includes pop-up blocker! Only $14.95/month -visit http://www.juno.com/surf to sign up today!