How to ground a minn kota trolling motor and its battery on a fiberglass boat?

WyldFya

Cadet
Joined
May 21, 2013
Messages
8
How can I ground my battery and motor on a fiberglass boat? The only metal on the boat is a small 3/8" steel rim that goes around the boat. There is no good way to attach a wire to the rim either.

Any suggestions greatly appreciated.
 

WyldFya

Cadet
Joined
May 21, 2013
Messages
8
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

Also, I have a 55# thrust Minn kota, and the last two times I have gone out fishing, the charge has only lasted 20-30 minutes. This is after giving a full charge. Could this be due to the lack of grounding, or is it something else? I have taken the boat out 5 times. The first 3 times I had no problems, and ran the motor for 3-5 hours each time. The last two times the charge has only lasted 20-30 minutes.
 

scottmm73

Petty Officer 1st Class
Joined
Jun 9, 2012
Messages
261
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

What type of battery are you using? Sounds to me like you are not using deep cycle battery.
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

You don't ground the battery or the TM to the boat. Glass or aluminum, you always connect the TM ground and positive to the battery. Either directly or using a high amperage connector.
 

colbyt

Master Chief Petty Officer
Joined
Aug 9, 2012
Messages
824
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

How old is the battery? Are the cells full of distilled water? How has it been stored? How soon after use was it charged? Was the charge maintained?

Depending on the answers a one year old battery may be all done.
 

WyldFya

Cadet
Joined
May 21, 2013
Messages
8
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

What type of battery are you using? Sounds to me like you are not using deep cycle battery.

It is a deep cycle trolling battery.
 

WyldFya

Cadet
Joined
May 21, 2013
Messages
8
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

You don't ground the battery or the TM to the boat. Glass or aluminum, you always connect the TM ground and positive to the battery. Either directly or using a high amperage connector.

That is what I thought, but the local outdoor sporting shop told me to always ground the battery, and trolling motor.
 

WyldFya

Cadet
Joined
May 21, 2013
Messages
8
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

How old is the battery? Are the cells full of distilled water? How has it been stored? How soon after use was it charged? Was the charge maintained?

Depending on the answers a one year old battery may be all done.

The battery is 4 years old. I do not know if it was maintained with a charge or not, up until the last couple weeks, where it has always had a full charge, while not in use. There was one night where I did not charge the battery until the following morning. I have not checked to see if the cells are full of distilled water.
 

NYBo

Admiral
Joined
Oct 23, 2008
Messages
7,107
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

That is what I thought, but the local outdoor sporting shop told me to always ground the battery, and trolling motor.
I would be suspicious of any advice these people give you. :eek:
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

That is what I thought, but the local outdoor sporting shop told me to always ground the battery, and trolling motor.
They don't know what they are talking about. Have your battery load tested.
 

colbyt

Master Chief Petty Officer
Joined
Aug 9, 2012
Messages
824
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

4-5 years on a deep cycle battery is a fairly typical life if very well maintained. To confirm, charge it fully and take it to a shop for a test. I suspect a weak or dead cell.
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

That is what I thought, but the local outdoor sporting shop told me to always ground the battery, and trolling motor.

That's why they are are sporting goods shop and not a boat dealer. :facepalm:
 

Fudoshin

Cadet
Joined
May 26, 2013
Messages
7
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

yeah the negative on the batteries is all the ground you need, like you said already I have a tri hull and finding a ground location is like finding a leprechaun unless you'd attach to any navigation switches you may have, but your normal hook up is all you need.
 

WyldFya

Cadet
Joined
May 21, 2013
Messages
8
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

Also, I have a 55# thrust Minn kota, and the last two times I have gone out fishing, the charge has only lasted 20-30 minutes. This is after giving a full charge. Could this be due to the lack of grounding, or is it something else? I have taken the boat out 5 times. The first 3 times I had no problems, and ran the motor for 3-5 hours each time. The last two times the charge has only lasted 20-30 minutes.

Took the boat out again today, with a brand new battery, and same problem. So now I'm sure it has to do with the motor. I'm assuming a have a short somewhere in the motor. How difficult is it to fix a problem of this nature, or what other problems could cause this?
 

nite fisherman

Seaman Apprentice
Joined
Jul 14, 2011
Messages
33
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

My unprofessional opinion is sounds like the seal in the tm is letting water into the motor housing and that is what is draining your battery so quickly. Water getting in there is causing the short.
 

WyldFya

Cadet
Joined
May 21, 2013
Messages
8
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

My unprofessional opinion is sounds like the seal in the tm is letting water into the motor housing and that is what is draining your battery so quickly. Water getting in there is causing the short.

I checked the motor housing, and it was full of water. I suspected a short, but did not think of water causing that. When taking the housing apart, I noticed there was a missing washer, and that the outer chamber wall for the housing was installed backwards.

I got everything dried out, reassembled, and tested it out, in the shop. It ran it for 30 minutes non-stop, full speed, with no sign of lost speed. Looks like I'll need to order some parts.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

I checked the motor housing, and it was full of water. I suspected a short, but did not think of water causing that. When taking the housing apart, I noticed there was a missing washer, and that the outer chamber wall for the housing was installed backwards.

I got everything dried out, reassembled, and tested it out, in the shop. It ran it for 30 minutes non-stop, full speed, with no sign of lost speed. Looks like I'll need to order some parts.

Running a troller for that long out of the water is not a good idea since water is used for cooling.
 

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,908
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

The shop said they should be grounded, mabe they meant bonded? 2 different things.
Grub
 

ajax5240

Petty Officer 2nd Class
Joined
Aug 6, 2011
Messages
134
Re: How to ground a minn kota trolling motor and its battery on a fiberglass boat?

Grounding the battery to fiberglass would be like using your spare tire as the trailer ground. Just doesn't make sense, but it gives others a good laugh. I wonder if the guys at your local store there ground an electrical outlet in their house to the nearest 2x4 stud?
 
Top