How often do you charge your trolling motor batteries?  I have two batteries for trolling in my boat and I have been charging them after every fishing trip whether I used them a lot or not.  Is it possible to 'over charge' the battery?  Should I wait until the battery dies before I charge it?

i charge mine after every trip also   never had any problems

You should definitely resotore them to fully charged after each use.  Leaving a lead acid battery in a partially charged state allows an excess of lead oxide to build up on the plates and will decrease the life of the battery.

thanks guys, i was wondering because i accidentally charged one of my batteries for about 24 hours even though it still had about 50% voltage.  will that hurt it?

no matter how much or how little you use your batteries you should put them on charge as soon as you get back from fishing. never leave a battery with less that a full charge. Is you charger a smart charger? meaning it will charge the battery to full, then go on maintance mode, not over chargeing a battery? if so just plug it in and charge it will not over charge.

I use onboard chargers in my boats and they are plugged in 24/7/365, the only time the chargers are not plugged in is when I am fishing.