I am looking for a battery charger that can charge a 12v starter battery and two (24v) trolling batteries. Also something that can charge AGMs, Gels or just a wet batteries. I don't think I want anything that is permanently affixed to the boat. I was looking at the Professional Mariner, ProSport series, 12amp 12/24v or the 20amp 12/24v. Anyone used these, are they good or is there something better?