Deep Cycle Spec. Questions

[Nate W.]

I'm trying to figure out how long a trolling motor battery will last before it needs a charge. Most deep cycle batteries have a rating of XXX amp hours followed by reserve minutes. Correct me if I'm wrong, but don't I need to find out what the draw of my motor is before I have an idea of how long a battery will last? What's normal for low-speed trolling? 8 hours? 10 hours? I just bought the trolling motor, (Motor Guide, 30# thrust) and nowhere in the book does it say what the draw on certain speeds will be. I got the motor to take to Canada. I don't want to have my trolling motor die by noon each day, but then I don't want to spend more money than I have to. Thanks in advance, the Pros on this site are a great help to those of us with aspirations of adequecy.

[Kevin A]

Call your motor mfg and ask them about the amp draw. I had a smaller motor like this & I think it would pull 25 amps wide open. Run wide open for 1 hour & you've consumed 25amp-hours. If you have around a 75-100 amp*hour battery you've got 3-4 hours of wide open running time. Running wide open continuously for hours isn't usually needed though.

[ETT]

If you want to recharge over night with a std. 10 amp charger, you probably shouldn't draw your battery down more than 50%. So once you determine your total load in amphours you need a battery with twice that capacity. Good luck.