Wire size?

[graybeard2]

I want to move my battery to the front of my boat for better weight distribution. How heavy a wire do I need to run a small trolling motor and depth finder?

[hovermn]

6 gauge would be as light as you should go, but that's not saying 6 gauge is right on the edge. IMO, 6 is the right size. Unless you have wire laying around, just pick up a set of jumper cables and use them. I've been using them in hovercraft (6 gauge) for years.

I just mounted a bow mount trolling motor and plan on picking up a set of jumpers for power...

[solbes]

I'd try Minnkota's wire guide calculator. Either go to their HSOforum and work through them or try these below (same thing):

-Determine length of wire from batt to motor and double

-Determine max amp draw from your trolling motor

-Use Chart below to select wire size that gives loss of less than 1 Volt

Voltage Loss Chart

AWG 5 AMPS 10 AMPS 20 AMPS 30 AMPS 40 AMPS 50 AMPS

4 .0012V .0025V .0005V .0075V .01V .0125V

6 .002V .004V .008V .012V .016V .02V

8 .0032V .0064V .0128V .0192V .0256V .032V

10 .0051V .0102V .0204V .0306V .0408V .051V

12 .0081V .0162V .0324V .0486V .0648V .081V

For example with my boat:

20 feet x 2 = 40 ft

43 amp max draw (rounded down to 40 in chart)

Using 4 gauge wire: .01 x 40 = .48

Using 6 gauge wire: .016 x 40 = .64

Using 8 gauge wire: .0256 x 40 = 1.024

I went with 6 gauge because you are supposed to keep it below 1. Lower voltage losses will give better power and have less tendency to heat up.