I would look hard at the AGM and I would for the sake of weight and size take a real hard look at the NOCO Genius onboard chargers. All digital, AGM compatable, all digital. They are expensive ( in line with Minkota and cheaper than Dual Pro ) hook to batteries, mount and forget it. Just plug in when you get home, unplug and go to lake. The way you use boat you need at least a 10 amp charger. AGM require a higher output voltage than most chargers are regulated for on lead acid batteries. Your charger would charge them but probably never really top them off thus over time shorten the life of the battery.