Re: where to get 6 gauge wire ?
If you want flexable, welding cable (as quoted above) would be the best. It is constructed of many small strands making it 'soft', but it is more expensive. Cheap jumpers not as good. You need the large gauge because low DC voltage, like 12vdc, does not travel well for long distances without lots of loss. Loss in the cable is power (heat loss) that your motor is not getting. Larger cables gives more copper surface area, making it easier for electrons to move esp at high current like a trolling motor. The same applies to a degree to AC current. Thats why power lines are high voltage (in kV range) - to keep the wire size small.