Trolling motor on Pontoon Boat Current Draw

I have some questions about trolling motor current draw on a pontoon boat. I have an 18 foot toon that I'm building from the logs up. I am looking at putting a Minn Kota 55lb terrova with i-pilot on it. I found someone on the internet that has the same motor and they posted current draws that they logged while using the motor. At speed setting 5 in calm sea no wind he was drawing 8.40 Amps. I plan on using the motor at half throttle for 5 hours a day. This should be 42 amp hours total. Correct so far? I will also have a stereo running during this time. I have run my own tests on the stereo figure 2.5 amps for the stereo at a very loud volume which it won't be used at but just to be safe that's my figure. So that's an extra 12.5 amps. That's a total of 54.5 amps that need to be replaced each day to the battery correct?

Re: Trolling motor on Pontoon Boat Current Draw

I found this battery (Universal Battery 200 Amp-hours AGM Sealed Battery) which is 200 ah. It weighs 115 lbs but it would be in the middle of the boat under a seat and never be moved. I should never come close to bringing it down below half a charge. Is this all correct or did I miss something.

Re: Trolling motor on Pontoon Boat Current Draw

If setting 5 is top speed, that amp figure is off by about a factor of 5 or more.

Re: Trolling motor on Pontoon Boat Current Draw

Top speed is 10. Its half speed.

Re: Trolling motor on Pontoon Boat Current Draw

These figures are for a 55LB Terrova with i-Pilot. They were measured while on the water and are approximate.

Speed
Setting - Amps
1 - 0.90
2 - 1.58
3 - 3.03
4 - 5.27
5 - 8.40
6 - 12.70
7 - 17.50
8 - 23.50
9 - 30.15
10 - 36.40

Re: Trolling motor on Pontoon Boat Current Draw

And those numbers will also vary significantly depending on water conditions, boat size, and load.

Re: Trolling motor on Pontoon Boat Current Draw

Will they vary? I feel like an electric motor will take a certain amount of power to turn a certain RPM. The "speed" state above is more of a motor RPM. The knots of the boat will very but the motor should in theory turn the same RPMS at a "Speed" setting of 5 no matter the weight of the boat or wind conditions. I could be way off. I know with gas engines they will burn more fuel at a 1500 RPMs under load compared to the same motor running at 1500 RPM's in neutral but i thought Electric motors were more stable in consumption compared to gas engines.

Re: Trolling motor on Pontoon Boat Current Draw

biglurr54 said:

Will they vary? I feel like an electric motor will take a certain amount of power to turn a certain RPM. The "speed" state above is more of a motor RPM. The knots of the boat will very but the motor should in theory turn the same RPMS at a "Speed" setting of 5 no matter the weight of the boat or wind conditions. I could be way off. I know with gas engines they will burn more fuel at a 1500 RPMs under load compared to the same motor running at 1500 RPM's in neutral but i thought Electric motors were more stable in consumption compared to gas engines.

Click to expand...

Electric or gas is doesn't matter. It's going to take more energy to turn the motor the bigger the load gets whether it's getting that energy from fuel or a battery.

Re: Trolling motor on Pontoon Boat Current Draw

Electric trolling motors will vary with load and wind conditions somewhat... think of prop slip.. a heavier boat, or wind pushing against will cause the motor to fight prop slip in the water to keep the boat moving at the same speed. I don't have real world numbers for you at this point but I know a electric motors power consumption(amps x volts) will increase with pitch adjustments, and drag.

Fun fact/side note: this is actually a very common ptoblem to overcome in rc planes in respectto doped controllers, motor size, prop length, prop pitch and battery capacity.

Bill

Re: Trolling motor on Pontoon Boat Current Draw

Meant to say fight prop slip to keep the water moving past the prop at the same speed, not keep the boat moving at the same speed.

Bill