Trolling motor battery

[Ric66]

Hi,

I'm retiring at the end of this year and my plan was to buy a bow mounted trolling motor with ipilot and spot lock as my reward for the 30 years I've put in at my work. Well, I said the hell with it, if I'm going to buy one anyway might as well buy it now.

The question I have is with regards to the TM battery. My boat comes equipped with a plug at the bow. Do I have to worry about connecting my starting and TM battery's negative posts or just keep the batteries isolated?

I'm worried about the electrolysis between my aluminum boat, the starting battery and all that is connected to it, and the trolling motor when it is in the water. I've searched online and everyone seems to have a different opinion. Am I overthinking this?

[Frogger]

I think it’s a good question and yes everyone has different opinions. I ended up isolating mine from the boats starting battery (12v) but found out that the ground from the 24v trolling motor system made its way back to the 12v system when I connected the depth finder (wired to the boats 12v) to the trolling motors (24v) transducer via a connector cable. Remember your 12v is grounded through your hull with the outboard. Nothing I could do other than run the depth finder to one of the (2) 12v trolling motors batteries. I decided not to. I stayed with the setup as is with keeping it on the boats 12v system. I wasn’t seeing any interference and after talking to a tech at minn kota he confirmed it as well I would be good. Just a little frustrating at first realizing the grounds were connected.  They do suggest to run the trolling motor batteries isolated from your starting battery as the draw is inconsistent on the batteries and not good for them. For example, if your trolling motor is 24v, and you tie another 12v to make 24v for the trolling motor, but leave one of them tied to your main starting battery, you may find that you can’t start your main motor after a few hrs of fishing or have problems down the road with inconsistent draw / charging on them. Just one of many opinions out there. Congrats on the retirement. 

[chowder]

I strongly advise you to consider all aspects of the bowmount purchase:

1.) A bowmount system is composed of 4 parts a) the bowmount b) the batteries c) the controller (foot, bluetooth remote etc) and d.) the onboard charging system.

2.) Think hard thru all you will want this system to accomplish because there are several factors to consider; a) Are you going to be using the bowmount only for rod in hand fishing (drifting rivers, jigging, bass techniques, etc) or are you going to be using it for the aforementioned purposes as well as for trolling? b)  If you are using it for trolling, will you be using it alone to provide propulsion or in conjunction with a main or kicker motor doing the 'pushing' and the bowmount doing autopilot duty?

3.) How big (lbs thrust required) and tall (shaft length required) is your vessel and are you going to stay in that boat for quite awhile.

4.) the answers to all these questions are pretty important if you want an integrated system that will meet all your needs. 

-Tight Lines!

 

P.S. FYI I use a 22' aluminum outboard boat w/ 220 hp main, 9.9 kicker to do charters on the Niagara river, Finger lakes, Long Island Sound and Lake Ontario and Lake Erie .This vessel is equipped with a 115 lb thrust Min Kota Terrova AP Spotlok, Saltwater 36 volt unit, 3 batteries and a 4 bank charger (the 4th bank charges 1 of this boats starting batteries) I use both a bluetooth controller and a corded foot pedal,. I have learned the hard way to think as much as I can about overall considerations and what I might do next that I'm not doing now before making a bowmount investment.

Edited April 17, 2022 by chowder
add info

[Ric66]

2 hours ago, Frogger said:

I think it’s a good question and yes everyone has different opinions. I ended up isolating mine from the boats starting battery (12v) but found out that the ground from the 24v trolling motor system made its way back to the 12v system when I connected the depth finder (wired to the boats 12v) to the trolling motors (24v) transducer via a connector cable. Remember your 12v is grounded through your hull with the outboard. Nothing I could do other than run the depth finder to one of the (2) 12v trolling motors batteries. I decided not to. I stayed with the setup as is with keeping it on the boats 12v system. I wasn’t seeing any interference and after talking to a tech at minn kota he confirmed it as well I would be good. Just a little frustrating at first realizing the grounds were connected.  They do suggest to run the trolling motor batteries isolated from your starting battery as the draw is inconsistent on the batteries and not good for them. For example, if your trolling motor is 24v, and you tie another 12v to make 24v for the trolling motor, but leave one of them tied to your main starting battery, you may find that you can’t start your main motor after a few hrs of fishing or have problems down the road with inconsistent draw / charging on them. Just one of many opinions out there. Congrats on the retirement. 

Thanks for the feedback Frogger. It's hard for me to believe the answer hasn't already been determined and it would be standard for all trolling motors. Probably because everybody's boat is wired differently. I guess the best thing is to try it one way and if I see interference, change it.

[Ric66]

2 hours ago, chowder said:

I strongly advise you to consider all aspects of the bowmount purchase:

1.) A bowmount system is composed of 4 parts a) the bowmount b) the batteries c) the controller (foot, bluetooth remote etc) and d.) the onboard charging system.

2.) Think hard thru all you will want this system to accomplish because there are several factors to consider; a) Are you going to be using the bowmount only for rod in hand fishing (drifting rivers, jigging, bass techniques, etc) or are you going to be using it for the aforementioned purposes as well as for trolling? b)  If you are using it for trolling, will you be using it alone to provide propulsion or in conjunction with a main or kicker motor doing the 'pushing' and the bowmount doing autopilot duty?

3.) How big (lbs thrust required) and tall (shaft length required) is your vessel and are you going to stay in that boat for quite awhile.

4.) the answers to all these questions are pretty important if you want an integrated system that will meet all your needs. 

-Tight Lines!

 

P.S. FYI I use a 22' aluminum outboard boat w/ 220 hp main, 9.9 kicker to do charters on the Niagara river, Finger lakes, Long Island Sound and Lake Ontario and Lake Erie .This vessel is equipped with a 115 lb thrust Min Kota Terrova AP Spotlok, Saltwater 36 volt unit, 3 batteries and a 4 bank charger (the 4th bank charges 1 of this boats starting batteries) I use both a bluetooth controller and a corded foot pedal,. I have learned the hard way to think as much as I can about overall considerations and what I might do next that I'm not doing now before making a bowmount investment.

Thanks for the info chowder. I think I've considered most of the things you mentioned. I will be using a kicker for propulsion and the TM for direction. I've heard people put a rudder on the TM to save battery power. I've also learned the hard way (wasted money). The best way I've found to make decisions like this is to talk to others who have similar boats/set ups.

[chowder]

I do have a rudder on my bowmount. I definitely noticed a difference in the capability of the motor to maintain boat position in the strong currents on the Niagara River . I'm not sure how much difference it has made when using the bowmount as the autopilot. What I have noticed is how important it is to begin immediately using the kicker in conjunction with the bowmount as soon as I start trolling, especially with 4 customers onboard going into a chop. I got into the habit of using the bowmount itself to troll in an effort to get fishing asap and then I would get busy resetting lines etc and run on just the bowmount for longer than I was aware and with 4 customers + me the batteries would get depleted and my electric planer reels which are wired to the bowmount batteries will run pretty slow getting the boards in at the end of a trip.

[Prof T]

I also run kicker for propulsion and bow mount, 80 lb Terrova with a big rudder to steer. I troll current and think the rudder provides a lot truer course with less course correction. Note that when using the autopilot feature, there are two modes.

 

One lays down a virtual course. If you drift or are pushed off of it, the trolling motor will work to bring you back onto that "line" and then continue. Very choppy on a windy day.

 

The other (on mine it's called Legacy") you lock in a direction only. If you drift or are pushed off of it, it maintains the direction only even if you are 30 ft to the side of your original plan. That's the one I use. Saves a lot of over correction.

[Ric66]

Thanks guys. Very helpful information!

[Ric66]

On 4/18/2022 at 6:54 AM, Prof T said:

I also run kicker for propulsion and bow mount, 80 lb Terrova with a big rudder to steer. I troll current and think the rudder provides a lot truer course with less course correction. Note that when using the autopilot feature, there are two modes.

 

One lays down a virtual course. If you drift or are pushed off of it, the trolling motor will work to bring you back onto that "line" and then continue. Very choppy on a windy day.

 

The other (on mine it's called Legacy") you lock in a direction only. If you drift or are pushed off of it, it maintains the direction only even if you are 30 ft to the side of your original plan. That's the one I use. Saves a lot of over correction.

I've now install my bow mounted trolling motor. Wondering where do you put the rudder on? I've seen ones attached to the shaft but then how do you stow it on its bracket? And this question is from left field but why aren't there sacrificial anodes on a trolling motor? I believe I've read they do put them on ones used for salt water.

[Prof T]

this is the one I use. Hose clap to motor housing, hangs below, stows straight forward (watch your head while on trailer)

 

https://leelock.com/product/lms-01-magnum-skeg/