Troling motor wireing size?

[pikefisherman]

I would like to use my 55lb trust motor to pull my 20 foot pontoon for trolling, now and then. I would be taking it off the fishing boat and using it on pontoon now and then. Battery is in back on pontoon. Would it make sense to just buy a new battery and mount it on the front of pontoon, for trolling motor, rather than run new wire from back of boat? If not what size wire would I need? I am thinking # 8 or # 10. For charging I will unhook battery, and recharge on charger, not use the outboard motor.

 

[colbyt]

Re: Troling motor wireing size?

Wire size is based on ampacity and distance. Some tables factor in the up and back, some don't. Minn-Kota has table on their site. A 30# needs at least a #6 wire for a 14' boat if it is to be used on high speed. I imagine a second battery will be about as cheap as the proper wire.

 

[fishrdan]

Re: Troling motor wireing size?

For 10% voltage drop at the max draw of approximately 55 amps you would need 6AWG wire, for 5% voltage drop you would need 3AWG. If running mostly at lower speeds 6AWG would be OK, if running most of the time at higher speeds go with the 3AWG as the wire will have less voltage drop.

6AWG - 10% of battery voltage is about 1.26V, or 11.4V to the trolling motor at max speed
3AWG - 5% of battery voltage is about .63V, or 12V to the trolling motor at max speed.

Having the battery up front by the trolling motor will not induce voltage drop due to the additional long wire runs..... And as colbyt said, the additional battery will probably be the same price as running wire to the back.

If you're going to run wire, go to genuinedealz as their "marine" wire is about the same price as the Home Depot stuff. Much better wire and their free shipping will have it to your door step in 2-3 days.

 

[pikefisherman]

Re: Troling motor wireing size?

Thanks got it, will be easer to have the battery up front also, to take off for charging. I thought the wire would be costly.