PhilAddison wrote:All you need to do is add your cranking battery in series with a jumper wire. If youre not adding a 4th battery, make sure the cranking battery is a large high capacity battery if you fish greater than 8-10 hrs. in a day with limited outboard motor use.If you do this, make sure you connect the ground wire from the trolling motor to the cranking battery ground, otherwise electrolysis will occur.Jones Trolling Motor Services870 773 3474Motorguide/MinnKota/PowerPole/Lowrance/Humminbird