Please comment on boat size and speed, hrs of constant trolling. Trolling data for all!

Looking to troll at 2.5 mph with 36v Garmin force trolling motor. What battery set up do I need
The biggest they make for 36V. 2.5 is fast will require a lot of amp draw. Not an easy question to answer, especially with no info other than trolling motor brand. But regardless, you'll need lots of power. 100AH won't do it for more than 3 hrs or so.