Electric motor for trolling fishing?

Marco Bernardini

Marco Bernardini

Active User
Registered
Joined
Dec 17, 2012
Messages
745
Tonight a friend told me he want to try to use on his 4.70 metres fishing boat an electric motor for trolling fishing (2-4 knots, good for bonitos, mackerels, dorados, amberjacks - tuna requires far more speed
[*]).
His idea is to keep the batteries charged with some solar panels, making with them a sort of bimini top over the boat.
I suggested him to adapt the starter motor of a diesel over the foot of a small outboard.
Other suggestions keeping the budget low are very welcome: the price of a 50 lbs Minnkota trolling motor here is over 400 euro ($544)…

[*] Here is why the modification of cars to make them faster is called "tuning".
 
A starter motor might not be the best choice. They are designed to put out a lot of power for a very short period of time. They also don't have bearings, but rather bushings. When used for starting, the normal duty cycle is <15 seconds on, followed by 1 minute off. They will run longer with a light load, but the current draw is still substantial. It might be possible to control a starter motor with a PWM controller. I'm pretty sure the new Minnkota motors are now BLDC, but they may still be using brushed DC motors with a PWM controller.

If you can find a BLDC motor and controller, that would be a good fit. Also a golf cart motor may work, as might a larger battery drill motor.
 
JimDawson said:
A starter motor might not be the best choice. They are designed to put out a lot of power for a very short period of time. They also don't have bearings, but rather bushings. When used for starting, the normal duty cycle is <15 seconds on, followed by 1 minute off. They will run longer with a light load, but the current draw is still substantial. It might be possible to control a starter motor with a PWM controller. I'm pretty sure the new Minnkota motors are now BLDC, but they may still be using brushed DC motors with a PWM controller.

If you can find a BLDC motor and controller, that would be a good fit. Also a golf cart motor may work, as might a larger battery drill motor.
Click to expand...

Thanks for the suggestions, Jim!
I think here it's not easy to find a golf cart… maybe a soccer cart :D
 
I think some of the new starter motors are permanent magnet, if so would they be more efficient. If so you could remake the ends to run ball bearings.
Greg
 
a while back someone did a write up about using a 12V power drill motor, mounted in a water tight container and mounted the variable speed / reversing trigger on a post that was above water. he claimed it worked great on a car battery,
try searching "instructables"
 
I dont think Solar panels would charge fast enough to keep up with the consumption, especially from something like a starter motor.
Around here, electric trolling motors are very popular with the barra fishermen. They mostly use the MinnKotas You need to have a separate battery for your troll motor and hook it up to charge from your main motor when you are running that. I have never seen a solar setup to keep the charge on a troll motor.

Cheers Phil
 
12bolts said:
I dont think Solar panels would charge fast enough to keep up with the consumption, especially from something like a starter motor.
Around here, electric trolling motors are very popular with the barra fishermen. They mostly use the MinnKotas You need to have a separate battery for your troll motor and hook it up to charge from your main motor when you are running that. I have never seen a solar setup to keep the charge on a troll motor.

Cheers Phil
Click to expand...

My friend use the boat for a few hours during the weekends, so the battery would have 5 days of recharge between every usage: the surface of solar panels required to directly run a motor would become a nice sail :biggrin:
Anyway a connection with the main motor is planned.
For "barra" you mean "barracuda"? It's just a few years we have them here in Northern Mediterranean, and trolling fishermen are a bit scared of them.
 
No Marco,
As in barramundi, lates calcarifer barramundi.jpg
Good fighting and eating. Much tastier than wormy barracuda

Cheers Phil

barramundi.jpg
 
Unless you make a lucky find, most of the items that have an electric motor to suit are also not cheap. Electric wheelchairs, golf carts as someone mentioned, and the like. The problem is not only getting one large enough to be useful but also to get a speed controller that is efficient so you are not using all that power just to make heat. That is the big reason most electric boat motors are going brushless.

You also will want to go beyond 12V. Smaller wires. Less energy lost as heat. A nearly 5 m. boat assuming it is not some skinny canoe is going to be using close to 1kw to push near 4 knots.

It would be a fun project but be sure to realize that you would be doing it for fun. By the time you bought 3-4 gel batteries, the solar cells, the motor, charger and speed controller along with the mechanical parts (shaft, prop, mounting) you can pick up a little 2.5 hp 4-stroke and probably 10 years of gas more cheaply.

Now there a really cheap way to go 2-4 knots all day long without using any fancy motor. It is called a sail. :)
 
You must log in or register to reply here.
Back
Top