I check the water levels on my golf cart every week or two. I was told I didn't have to do this with my boat batteries but I guess I'm gonna have to start checking those levels too based on what I'm reading here. I also have a new Minnkota 3 bank charger and leave my boat charger plugged in all the time since the charger has the trickle mode which only tops off batteries after they have been fully charged. Do you suggest I leave my charger unplugged after fully charging u til the night before my next outting?