Battery Charging

[Hogg Tyed]

I got a new battery the other day. Deep cycle trolling battery. The guy at the store told me slow charge is best and will make the battery last longer. I purchased a 1.5 watt trickle charger. I was told the batteries arrive at 8 percent charge. It has been charging for 36 hours and is still not at full charge. How long should it take to charge all the way up? Is the information I received good information. I have a 10amp charger. Will it hurt my battery charging it with it then maintaining the charge with the trickle charger? I hate to ruin a 100 dollar battery.