Wait....G might be on to something I missed....That does look like an automotive battery.

I now ammend my list above.......ONLY USE MARINE DEEP CYLCE BATTERIES FOR TROLLING. There is a difference in how they are made. Deep cylcles have more and thicker plate areas which allow for the storage of more power and the loosing of it over time. Starting batteries have less and thinner allowing for max power for a shorter time...basically.

If you've been running starting batteries....this is why you've gotten bad service life and have had to cut so many trips short. Whatever battery you replace with, make sure it says "Maring/RV Deep Cyle on it".

All of the above still apply though as far as other things to look at to maximize troll time.

Wannabe...