trolling motor wire?

  • Profile photo of coletrain01coletrain01
    Participant
    Rochester MN
    Posts: 193
    #1267104

    hello, im mounting a bow mount on my boat and my batteries are in the back of the boat. im wondering what gauge wire i should use to run it back to the batteries? thanks

    Profile photo of coletrain01coletrain01
    Participant
    Rochester MN
    Posts: 193
    #862503

    oh and its a 12volt motor and #40 thrust if that matters

    avatarses
    Participant
    Mississippi River
    Posts: 167
    #862512

    Hope this helps.

    avatarses
    Participant
    Mississippi River
    Posts: 167
    #862515

    What is Amp Draw?
    • Amp draw is the measurement of electrical current drawn from a storage battery (or battery), while the trolling motor is being operated at maximum speed.
    • Minn Kota ‘s published amp draw figures represent actual on the water conditions (with all of the motor ‘s wiring, switches and circuitry in the electrical system as the test measurement is taken).
    • Approximate length of running time when operation a trolling motor at full power can be determined with a motor ‘s amp draw and the battery amp hour rating.
    Example: A single 120 amp hour, 12 volt battery and a 12 volt trolling motor drawing 20 amps at the highest speed setting will run for about 3.4 hours.
    • The formula for the calculation is as follows:

    .85 A.H.R. = Hours of running time. (A.H.R.= Battery Amp Hour Rating)
    M.A.D. (M.A.D. = Motor Amp Draw)

    • As the speed setting is reduced the motor amp draw is also reduced.
    • A motor drawing 30 amps at high speed may only draw 5 amps at the slowest speed. The same motor that will theoretically run about 3.4 hours at high speed will run for over 20 hours at the slowest speed.

    | Top of Page |

    What gauge wire should I use for my trolling motor
    If the incorrect gauge wire is used, there will be a voltage loss to the trolling motor causing a decrease in power and heating of the wires.

    Follow the steps and the chart below to determine the proper wire gauge to use.

    Step 1.
    Determine maximum amp draw of your trolling motor and round up to nearest 10.

    Step 2.
    Measure distance from the battery to the power outlet or trolling motor connection.

    Step 3.
    Take the determined length (Step 2) and multiply by two.

    Step 4.
    Select a gauge of wire you think may be applicable. 10 AWG is a good starting point.

    Step 5.
    Consult the Voltage Loss Chart to determine voltage loss per foot so you may match the wire gauge to be used.

    Step 6.
    Take the Determined Length (Step 3) x 2 = Doubled Length. Take the Doubled Length x Voltage Loss = Total Voltage Loss.

    Step 7.
    Work through equation to determine best gauge wire to be used. The best gauge selection will be matched with the lowest voltage loss.

    For optimum performance, voltage loss should be between zero and one, but no greater than one.

    Example: You want to run 20 ft. of wire in your boat , and the maximum amp draw of the trolling motor is 37Amps.

    Step 1.
    Round up the amp draw from 37 to 40Amps.

    Step 2.
    20 ft. of wire which is needed.

    Step 3.
    Take 20 ft. x 2 = 40 ft.

    Step 4.
    Starting with 10AWG. Check the chart above for 40Amps and 10AWG.

    Step 5.
    .0408V is charted for the voltage loss.

    Step 6.
    Take 40 x .0408 = 1.632V – Not acceptable over 1V

    Try 6AWG. In working through the equation it equals.064 – which is under 1 volt, which is acceptable.

    Profile photo of coletrain01coletrain01
    Participant
    Rochester MN
    Posts: 193
    #862630

    well i bought some 8 awg from fleet farm today that said it is for marine use with trolling motors. so you think i will need heavier than that? it will be about 17-18′ by the time im done probaly

    Profile photo of coletrain01coletrain01
    Participant
    Rochester MN
    Posts: 193
    #862633

    well i did some searching and it looks like most use 6awg. i guess ill take the 8awg back. fleet farm didnt have anything bigger than 8awg so ill have to go elsewhere

    avatarHot Runr Guy
    Participant
    Posts: 442
    #862655

    Quote:


    well i did some searching and it looks like most use 6awg. i guess ill take the 8awg back. fleet farm didnt have anything bigger than 8awg so ill have to go elsewhere



    If you’re nearby a Gander Mountain, the store by me (in IL) has 6AWG Ancor marine wire on a spool, sold by the foot.
    HRG

    Profile photo of coletrain01coletrain01
    Participant
    Rochester MN
    Posts: 193
    #862658

    sweet ill check it out, thanks

    avatarjlynchminn
    Participant
    Rochester, MN
    Posts: 33
    #862785

    I searched for a long time for 6 Ga marine wire around here, but came up empty. Ultimately I bought some outdoor 6 Ga wire by the foot at Home Depot. As long as your wire and connectors are protected from the elements, I would think the outdoor wire would be fine. Gander Mountain carrys plenty of crimp-on connectors for hooking up 6 Ga wire to your battery.

    Profile photo of coletrain01coletrain01
    Participant
    Rochester MN
    Posts: 193
    #862827

    thanks guys. ill check out home depot this week and see what they got. im sure gander mountain wants a pretty penny for wire there (just like everything else)

    Profile photo of jon_wbljon_wbl
    Participant
    Posts: 221
    #862955

    Ive seen that package of wire they sell at FF. It is not marine grade wire. Make sure you use the marine wire so you are not doing it over too soon.

    Profile photo of Denny ODenny O
    Participant
    Central IOWA
    Posts: 2,086
    #862999

    Give NAPA a shot. Marine grade!

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