# Trolling motor issues



## firecat1981 (Nov 27, 2007)

9ft is a long distance for TM leads, what guage size is the wire? It's usually written on the wires sheathing. You might be suprised to see how thick of wire you need to cover that distance. Also what kind of TM is it?


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## logandorn96 (Mar 27, 2011)

wow i cant belive i forgot to put what kind of trolling motor it is, well its a 54lb thrust motorguide and it has 6 guage wire.


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## Brett (Jul 16, 2008)

Trolling motors draw about 1.2 amps per pound of rated thrust.
So at maximum load a 54 lb thrust trolling motor draws (54 x 1.2 = 64.8) about 65 amps.
So using the calculator at the bottom of the page in the link...

http://www.powerstream.com/Wire_Size.htm

it's easy to determine voltage drop with a set of 9 foot long cables.
input:  copper wire
          gauge size of wire (6)
          voltage  (12VDC)
          length round trip (9x2=18)
          draw in amps (65)

then hit the calculate button...results shown

voltage drop 0.951 volts
voltage loss 7.93%

Maximum loss should be no more than 3%, you've got double that.
you need a heavier gauge wire for that setup at maximum draw.
According to the calculator, at maximum thrust, you'd need a 2 gauge wire
for a 9 foot distance from battery to trolling motor


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## logandorn96 (Mar 27, 2011)

will this cause it to over heat, cause the connector to the breaker burnt me when i touched it


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## firecat1981 (Nov 27, 2007)

yes, either that or a short somewhere.


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## Brett (Jul 16, 2008)

Current flow through wires results in voltage drop caused by resistance.
That drop in voltage due to resistance ends up in being converted to heat.
The greater the voltage loss the greater the amount of heat produced.


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## logandorn96 (Mar 27, 2011)

SO i can get a thicker wire, or just shorten the distance between the TM and battery


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## logandorn96 (Mar 27, 2011)

How close can the battery be to the gas tank?

If you can imagine this,

I would keep my battery under the front deck, but the deck had an extension put in, where the original deck ended it came down to the floor and has 2 football size holes before it goes to the extended deck that has a gas tank there.

I mean there a good 2 foot apart and have a wall in between the tank and battery, but the wall has 2 football size holes.


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## firecat1981 (Nov 27, 2007)

Is the extesion open on the end? if so that should be enough ventilation and you should be ok. For protection put some rubber boots over the leads and terminals on the battery.

But....I would really only relocate the battery if you think it will help you balance your load better. Other wise I would just run the 2ga wire like Brett said. Does your boat have one or 2 batteries?


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## logandorn96 (Mar 27, 2011)

the extension can be either open or closed if that makes sense.

it has 2 batteries. And i usually keep them under the console but if i move the battery i can put my tackle, dry box, first aid kit/tools box under it.

and my boats back heavy so it might actually help


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## firecat1981 (Nov 27, 2007)

Well if it's dragging in the rear, moving a battery up front will help and allow you to just shorten your wiring. Just make sure the compartment with the gas tank is well vented!


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## logandorn96 (Mar 27, 2011)

NICE! thanks for the help


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