Electric trolling motor size for 16' inflatable

[spoolin01]

I want to be able to troll slower for flat water small lake fishing and am considering a transom mount electric trolling motor. I've never used one, don't know anything about them. The boat is a 16' flat bottom inflatable Achilles w/40HP outboard, probably 1000-1200 lbs under way. Minn Kota and Cabelas are offering some incentives on the variable speed Endura Max motors, and I need advice which one to get. I'm leaning towards the 55lb thrust model, but there are also 40/45/50 models. Cabelas is adding a $20 discount just to the 55 model. Looking at thrust recommendations, I'm wondering if the 55 is a good match? I don't want to end up with min speed still too high. Is there a good selection of prop pitches if I find I need to prop down some from the installed prop? I'm already at the lowest prop for the outboard, and still get 2 knots at min idle. I'd like to get down to 1 knot or even less. ​

 

[Scott Danforth]

I fished for years on a 17' long bass boat with a 36# thrust trolling motor. A 55# would be fine unless your bucking heavy winds. Problem will be batteries. Not sure how much room you have in your inflatable

 

[spoolin01]

I'm more concerned that the minimum setting might still be too high, with such a light boat.

 

[Scott Danforth]

You can watch the prop turn on low setting

 

[spoolin01]

You can watch the prop turn on low setting

LOL, now that's news you can use! thks

 

[Silvertip]

55# on that boat would be more than adequate and it will run as slow as you want/need. There is not a wide selection of props for electric trollers like there are for gas outboards because electric motors must use props that result in a compromise between speed and current draw. High pitch props would lug the motor causing high current draw. Low pitch props reduce the load but they also lower the speed -- hence the compromise. The motor manufacturers have this situation figured out so the stock prop is usually best. There are different props but they are different to reduce noise or to work through weed beds more efficiently. Battery selection will be something you need to research more than the motor.

 

[spoolin01]

Thanks for all the help, I'll get the 55#. If I use a battery switch to protect reserve capacity in the starter battery, do you think a total of two Group 27 marine starter-type batteries would be enough for say 4 hrs of low speed trolling? There's probably room under the seat for two batteries in addition to the starter, if needed.

Are the common flooded marine starter types good for this, or is there a better choice?

 

[Silvertip]

Deep cycle for the trolley. Dual purpose or starting battery for the engine.