12v to 24v trolling motor???

wjhuskey

Seaman
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Apr 28, 2011
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My boat came with a 12v trolling motor but it recently locked up. It's pretty old so I was thinking about going with a 24v trolling motor. Will the existing wiring handle the 2 batteries ok? I'm planning on connecting cable straps from the existing battery to the new battery to tie them together. But will the wiring throughout the boat (that was installed for 12v use) handle the 2 batteries safely? Thanks in advance.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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My boat came with a 12v trolling motor but it recently locked up. It's pretty old so I was thinking about going with a 24v trolling motor. Will the existing wiring handle the 2 batteries ok?
probably not. however a new 24 volt trolling motor will have an installation manual with very specific wiring information.
 

vroom ZOOM

Petty Officer 1st Class
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Aug 15, 2017
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what gauge wiring do you have currently, and how long are the wires? I hope the trolling motor was not tapped in to the main wiring in the boat, and the TM has its own battery right?
 

wjhuskey

Seaman
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Apr 28, 2011
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what gauge wiring do you have currently, and how long are the wires? I hope the trolling motor was not tapped in to the main wiring in the boat, and the TM has its own battery right?
I'm not sure what gauge the wiring is but I'm pretty sure the boat originally came with a 12v trolling motor. It's a 16 ft boat and the wiring runs from the front to the back...and yes the trolling motor has its own battery, it's in the rear compartment.
 

BOBNEWTON

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Apr 28, 2019
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Typically speaking,

As voltage increases the amperage will decrease. Aside from other variables, a motor with the same thrust rating will draw half the amperage in a 24v arrangement vs a 12v arrangement, allowing for a conductor with half the current carrying ability.

However your best advice lays above, consult the manual. It should outline the required size of conductors. Length of wiring will play as role in this as well.
 

BOBNEWTON

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This is also a great time to ensure the cable run is fused appropriately.

If something were to happen along the length of your boat, you could be in real trouble really fast.

The motor will dictate amperage draw, not battery capacity. The wiring will be sized according, then fused in accordance to the wirings ability to carry current.
 

poconojoe

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Sep 10, 2010
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The most important things are proper wire size and proper location and size of the fuses. The wiring should be fused at the batteries in order to protect the wiring going to the motor.

As mentioned, your new motor will dictate all of this. It all depends on the amperage draw of that new motor.
Amount of batteries is (electrically) irrelevant.

You will need two 12v deep cycle batteries wired in series to supply the 24 volts needed.

Oh, if your existing wires are a larger size than needed, that's OK. Just make sure your fuses are sized according to the motor specs.
 
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