I just purchased a 14ft jon boat and I wanted to know what the best route would be..

A trolling motor with 2 deep cycle batteries
Or a outboard motor?

What would be the best for small rivers and lakes

I took the boat out just this past weekend with one deep cycle battery on board..went down river for about an hour then went back up river for a few hours and on my way back I could tell the battery was dying...so I wanted to get some help into what would be better