Wire size for xi3 Kayak Trolling Motor?

[Chaos10691]

I went out and bought 8 gauge THHN because that is what came in an install kit I found. However I believe that 8 gauge can only handle 40 amps correct?

If what I found is right the xi3 has a max draw of 52 amps. Should I go back and get 6 gauge?

Any advice appreciated. Thank you!

[MN Fisher]

Nope - 8AWG is good to up to 55 amps. Go ahead and use what you got.

[gulfcaptain]

If you can go 6awg then I would go 6awg over 8awg. I had an electrician tell me one day "wire is like a water hose, the thicker wire allows easier power transfer and constant voltage opposed to thinner which constricted causing loss of voltage. But again use what you got if you already have it or if not I would go 6awg if possible.

[osummerer23]

I have the xi3 on my 17' jon boat. I just installed 6awg wire over the weekend. 8awg was getting hot. I have the normal stock wire tied into an extra 4' (8' total) and was getting the wires hot on max speed setting on constant. 

 

Dont forget wire length is based on round trip from motor to battery and back. Not just motor to battery. 

[Fishingmickey]

I think the leads that come off the XI3 motor are 8GA. Not a 100% certain on that.

FM

[Chaos10691]

7 hours ago, osummerer23 said:

I have the xi3 on my 17' jon boat. I just installed 6awg wire over the weekend. 8awg was getting hot. I have the normal stock wire tied into an extra 4' (8' total) and was getting the wires hot on max speed setting on constant. 

 

Dont forget wire length is based on round trip from motor to battery and back. Not just motor to battery. 

So I'm in a 12 foot kayak. I suppose the only time I'd have it on full speed is when going place to place. 

[Fishingmickey]

1 hour ago, Chaos10691 said:

So I'm in a 12 foot kayak. I suppose the only time I'd have it on full speed is when going place to place. 

Probably not even then. I suspect you wont see much of a speed difference between 100 or 75-80% throttle.

[osummerer23]

On 5/14/2024 at 11:55 AM, Fishingmickey said:

I think the leads that come off the XI3 motor are 8GA. Not a 100% certain on that.

FM

If I recall from the weekend, they are 10awg. 

 

On 5/14/2024 at 3:24 PM, Chaos10691 said:

So I'm in a 12 foot kayak. I suppose the only time I'd have it on full speed is when going place to place. 

Full speed would be rare. I run 3mph with a 17' aluminum boat. Fishing buddy has a  similar power terrova on his old town yak and does 7mph (I believe, dont quote me). Only for crossing lake or in the bay. 

 

Trolling motor power consumption is not linear. It's more exponential. 1 Hour at max speed is not equal to 2 hours at half speed power usage wise. 

[Bankc]

The thing with wire gauge on a boat is the length of the run matters as much as the current draw.  It's not like house wiring where you have to pass sometimes arbitrary codes.  That's why trolling motors themselves usually have pretty thin wire on their prebuilt leads.  The electricity isn't running far through them, so they don't need heavy gauge wire to be effective.   

 

8 gauge wire should handle 55 amps so long as it's less than about 13 feet of wire run.  If you need a run longer than 13 feet, then I'd step up to 6 gauge, which would work up to around 19 feet of run.  Beyond that, and you'd need even thicker wire.  

 

If the wire is getting hot to the touch, that's a good indication that you need to go up a size in wire thickness.  Also, it's important to consider the connectors and make sure they're suitable for the amount of amps you push through them.  That's something a lot of people overlook.    

 

Usually it's better to go with a thicker wire than you need, just to give yourself some leeway.  But the standards that were developed were developed with some leeway in mind, so there's generally no harm in sizing it just right.  And technically, you can go too thick.  At some point, you'll be introducing more resistance by going thicker.  But at around 55 amps, you're probably not going to run into that problem.  That's more of an issue with running something like 10mA through 2/0 gauge wire or something.  

 

 

[Tennessee Boy]

You must include the wire size and the length to determine the voltage drop that will occur in the wire.  Using 8 gauge will not cause a fire but it’s a little small in my opinion.  You will see significant voltage drop when running the trolling motor on high.  When calculating the length of wire include the length to the trolling motor and back to the battery.  Consult a wire chart online to determine what you need.  I recommend this one.  

 

http://assets.***.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

Note:  Increasing the size of wire lowers the resistance,  it does not increase it.

 

 

[Chaos10691]

4 hours ago, Bankc said:

The thing with wire gauge on a boat is the length of the run matters as much as the current draw.  It's not like house wiring where you have to pass sometimes arbitrary codes.  That's why trolling motors themselves usually have pretty thin wire on their prebuilt leads.  The electricity isn't running far through them, so they don't need heavy gauge wire to be effective.   

 

8 gauge wire should handle 55 amps so long as it's less than about 13 feet of wire run.  If you need a run longer than 13 feet, then I'd step up to 6 gauge, which would work up to around 19 feet of run.  Beyond that, and you'd need even thicker wire.  

 

If the wire is getting hot to the touch, that's a good indication that you need to go up a size in wire thickness.  Also, it's important to consider the connectors and make sure they're suitable for the amount of amps you push through them.  That's something a lot of people overlook.    

 

Usually it's better to go with a thicker wire than you need, just to give yourself some leeway.  But the standards that were developed were developed with some leeway in mind, so there's generally no harm in sizing it just right.  And technically, you can go too thick.  At some point, you'll be introducing more resistance by going thicker.  But at around 55 amps, you're probably not going to run into that problem.  That's more of an issue with running something like 10mA through 2/0 gauge wire or something.  

 

 

I went ahead and picked up the 6 awg just to be safe.