Re: battery charger
a battery to quote silvertips is a bucket of electricity. The bigger the bucket and the lower the charge the more electricity the charger has to put back. So if the charger is a 10amp per hour and you used 60 amps out of the bucket then it will take 6 hrs to replace the charge. So the problem seems to be the max amps the charger will put out.
Im guessing you have a trolling motor and more than one battery so I would suggest looking at a on-board multi-bank charger so you can plug in and forget about the batteries while you sleep then just unplug and use the boat in the morning.