All good info here. For comparison sake: I have a 1880 Ranger Angler with a Ulterra 24V 80 Lb thrust group 27 batteries. Started out trolling with just the TM - couldn't reliably get all day out of the batteries even running with the wind. If you are planning to mostly troll the best solution is to bite the bullet and get a kicker motor. I got a kicker and now use it to push the boat and the TM to steer. We can easily go all day running the TM at 2-4. With the iPILOT it is very easy to continually adjust direction - this is really nice when the lake gets crowded with boats. I first considered going with bigger batteries but felt that would just add a little more time and not be reliable for all day. And as the trolling gets faster 2.0-2.5 and you try to run that TM over 5 it's just not going to last. Your batteries are only a year old - no need to replace them - better off spending the money on a kicker IMHO.