trolling motor speed

[fshnace]

I will be starting a build project soon and I am trying to figure motors out for the back of my boat. I fish electric motor only lakes, so my question is would 2 80lb thrust motors at 24v each motor be faster than 1 101lb thrust motors 36v motor. I am also thinking about 2 101lb thrust motors. That would be 6 batteries in the back of my boat. Any comments would help I dont know what to do. The front of the boat will have a 101lb thrust foot controlled motor. Thanks for the help

 

[Johny25]

I have been waiting for the day someone on here tried to plane a boat with trolling motors :lol: I say go with twin 101's and take lots of video

 

[thudpucker]

I like your idea. Make sure you can Row back home though.

I did some experimenting with a 12/24V motor and a small AL boat. The lake was full of stumps.
I think this motor had 35Lb thrust. Not like those Jet Propulsion lab blasters you have.
When your really fishing, you don't use them as hard as you would on a long trip to test the batteries.

I was pleasantly surprised that the batteries lasted as long as they did. One long day on the water and back home again.
Where you sit is important too. The level boat is easier on the Batteries.
The two batteries charged up overnight.
For a small lake, I think it's a great thing.
Time will tell though. Share a drawing with us. I'd like to see how you spread the weight out.

 

[Andyg]

I've got a 12ft v bottom with a 12volt 55lb transom mount trolling motor and it does just fine. On a full charge it will throw you off balance if you go from 0 to 5. I go out for about 5 hours and its only at 80% charge. Oh its a Minn Kota Endura c2 I believe. Two of those and you'd be moving right along.

 

[Zum]

I think it's better to have a trolling motor in the bow of a boat.Easier to control and they can pull you through the water.As far as speed,not real sure...less drag with with one,less weight,might be crap shoot.The nice thing about two,is the security,if one breaks down.Speed wise,around 5 mph....don't even think about planing.

 

[krawler]

Your top speed is only going to be about 5 mph or so with either setup. Trolling motors aren't built for speed.

 

[Johny25]

Your top speed is only going to be about 5 mph or so with either setup. Trolling motors aren't built for speed.

That is only because of the pitch/prop design. If someone was to get a few trolling motors like the poster is going with and had them propped with custom props (higher pitch) you could plane a small boat no problem

 

[lefty]

Who on earth makes an aftermarket prop for an electric motor besides Kipawa. Those don't add much speed.

 

[Zum]

Your top speed is only going to be about 5 mph or so with either setup. Trolling motors aren't built for speed.

That is only because of the pitch/prop design. If someone was to get a few trolling motors like the poster is going with and had them propped with custom props (higher pitch) you could plane a small boat no problem

I'll agree with you about the prop pitch determining the speed.
I can't agree about it and it's ability to plane.
Even at 101 lbs thrust,at most this would be equivalent to a 2hp;a doubt 3hp gas motor?
By the time you add the 3 batteries,it's now heavier then a 2 / 3hp gas motor,which was never able to plane the boat to begin with.
I would be interesting to see 2 or 3-101's on the back of a small aluminum though,with a different type(pitch) metal prop.

 

[JMichael]

A friend of mine has a very old MK trolling motor. So old, it doesn't say XX thrust, it says 3HP. :shock: It that was true back in the day(which I'm not sure how accurate that hp rating was back then), I gotta figure the actual HP rating of a 101 lb thrust has to be more than 3hp but how much more IDK.

 

[krawler]

The other issue with electric trolling motors is that you can only get about 1400 to 1500 rpm's out of them, not 4000 to 5000 like a gas motor.

 

[Johny25]

Your top speed is only going to be about 5 mph or so with either setup. Trolling motors aren't built for speed.

That is only because of the pitch/prop design. If someone was to get a few trolling motors like the poster is going with and had them propped with custom props (higher pitch) you could plane a small boat no problem

I'll agree with you about the prop pitch determining the speed.
I can't agree about it and it's ability to plane.
Even at 101 lbs thrust,at most this would be equivalent to a 2hp;a doubt 3hp gas motor?
By the time you add the 3 batteries,it's now heavier then a 2 / 3hp gas motor,which was never able to plane the boat to begin with.
I would be interesting to see 2 or 3-101's on the back of a small aluminum though,with a different type(pitch) metal prop.

With a little redneck ingenuity anything can be possible......lets not forget that :lol:

 

[Zum]

The other issue with electric trolling motors is that you can only get about 1400 to 1500 rpm's out of them, not 4000 to 5000 like a gas motor.

A lot of electric motors will spin 3500 rpm(use them at work)they probably go even faster,not sure about trolling motors.

 

[JMichael]

It's not always about the RPM. Look at a small airplane. It's turning the prop at 4-6 thousand RPM but compare that to the 60 or so RPM used to accomplish the first human powered flight. While it can't be done on the same scale, the same principle can be applied under water to make up for the difference. And electric motors can easily surpass a comparable gas engine. That's already been proven using radio controlled models with 2 cycle nitro engine vs electric motors. The electrics downfall compared to fuel is duration.

 

[lefty]

Well said. Still I think the bottom line here is how can we get our boat to go as fast as possible for as long as possible.
Around here some of the best fishing is on the electric only Reservoirs...
The Torqeedo motors are capable of turning the equivalent of a 9.9 but it takes 4000 to get one. Not to mention the 4 batteries for the 48V system to run it.
I am very interested in learning how to capitalize the most speed possible.

Planning the boat is not an issue. Whether it planes or not. We just want to go as fast as possible.
Please Elaborate!

 

[Zum]

There's something called "hull speed",long story short,it's the fastest your boat can go before it planes.
It's not determined by the motor(s)your using(gas/electric....etc) but by the boat itself and the type hull it has.
Google it(hull speed), if your having a hard time sleeping

I still say your not going to go much faster then 5/6 mph and then for how long.
More batteries = more weight....more weight = more power to plane,not to mention more money.

Anyways,theres lots of stuff on the web....have fun.

 

[lefty]

Makes since. Sorta. But what about torqeedos? They run much faster. With one extra battery. Could prop design have anything to do with it?

And for example.... if you run 2 rear 70 lb thrust motors. Is there much difference running 2 rear 55s?
70s run 24v system.
55s run 12v.

70s should run stronger longer. But where's the benefactor?

 

[Zum]

I haven't read to much on those torpedoes trolling motors.I do know they have a pretty big prop and I imagine the ones that go fast,are at least 48 volt and use lithium batteries,costing an arm and a leg. You gave a good reason for the 24v in your question....stronger,longer.
Plus if fishing current,wind or have a bigger/heavier boat the 24v will handle it easier and longer.
As far as props,of course they make a difference but you still need hp to move them and with electrics you also need batteries to store the power.

I have a old stealth 30lbs and a 55 lbs thrust TM,that I use 99 percent of the time.I tried the 30lbs by itself and its close to the same speed as my 55(.2 mph slower)but if it were windy,I imagine the 30lber would suffer.

 

[lefty]

Just caught back up with this post. Had the opportunity this summer to run my boat. 3-70# MK. side by side with a few other boats that had 2-101# MK. Both boats pretty much same weight length etc. each time the 101 slowly walked away and from what I see at the end of the day had much more reserve power leftover. With the 3-70# it takes 6 batteries. Same with the 101s. If u research the cost its not a heck of a lot more $$ just to buy the 101 motors.