how big a battery for a trolling motor

[Mike Churchill]

I know this is a "boat" question, but things posted there tend to draw few responses, so:

For pushing a small boat (12 foot Gregor) with a relatively small (34 lb. thrust) motor, how big a battery would you buy?

For AGM deep cycle batteries, it looks like the choices are around 32 amp hours, 55 amp hours, and 75 amp hours. The 75s are significantly heavier than the 55s and cost about $35 more.

I know that capacity is going to translate to more run time, but how much is enough for a day of fishing? (No gas motor yet but will probably get one next year.)

Thanks in advance for any advice.

Mike

[Ed Wahl]

Mike, I'm using a marine battery I picked up at wal mart the same time I bought my motor. Doesn't give amp hours on it but says 875 cranking amps, which means nothing really. I can say that I have yet to run it down while fishing. It has pushed my 8 ft pram quite a few miles(just ask Scott V.) and never slowed down. That's with a 28lb thrust motor. From what I hear fully charged battery should work all day, a long day at that, unless you run your motor on high a lot. Oh yeah, my battery cost more than the motor, still only around 60 bucks. Get a battery case at the same time, you don't want to be abusing the battery like you'll be abusing the case. Ed

[Scott V]

Not only did Ed's motor push his pram all day, but he also pulled me around in my pontoon, so that was an extra 350 lbs. counting me and my pontoon. So I think his battery is a good choice.

http://i3.photobucket.com/albums/y85/PsychoZ/IMGP0470.jpg

This pic is at the end of about a 10 hour day on the delta and he had plenty of power to pull me back. But not that I have my own trolling motor we can go further and longer.

[Hairstacker]

Great picture! :lol:

[Bill Kiene semi-retired]

I have a Minn Kota 'Enduro' tiller 55# thrust 12 volt electric motor.

It is the fastest 12 volt but at full throttle it runs through the battery faster than a small 34# or 28# thrust motor.

You might want 2 batteries so you have a reserve to get home. Maybe have a 32 and a 55 or 75?

Those big batteries are 'back breakers'.

If you keep your boat on a trailer you would not have to take them in and out.

If you get an outboard motor for that 12' Valco be sure to get max horse power if you can. That way when you are fully loaded you can get up on plan.