Johnson says #4 wire enough to cranking battery?

[tony_cliffy]

I'm wiring in a battery switch and called Johnson to inquire about necessary wire guage. They said #4 should be fine. I ask as the factory wire curerntly hooked to my cranking battery looks much bigger. <br /><br />I figured I'd need the same guage as they used between the motor and the cranking battery to connect my house battery to the switch. It is for emergency situations only.<br /><br />Oh, it is a 2004 Johnson 115HP 4-stroke.

 

[rickdb1boat]

Re: Johnson says #4 wire enough to cranking battery?

Wire Gauge Calculator

 

[tony_cliffy]

Re: Johnson says #4 wire enough to cranking battery?

Rick,<br /><br />Thanks for the link to a wire guage chart!<br /><br />I don't know the current pull of my engine during starting to size wire using a chart. In lieu of that I had called the manufacturer - was hoping someone could comment in their recommendation. I would tend to go with theie recommendation but note the engine came with larger wires from the factory.

 

[rickdb1boat]

Re: Johnson says #4 wire enough to cranking battery?

I don't know how far it is from your battery to the switch, but lets say it's 5 feet. With #4 gauge wire you can pull up to 200 amps. Way more than enough for your starter.... Depends on the length...Now if it's 8 feet away, you would need #2.....