I have just put a 788ci di on the front of my boat and I am getting some interference as soon as I step on the trolling motor. Motorguide said I needed a bigger cranking battery because thats were I have the graphs hooked up at. The battery that is in there now 625 marine cranking and 700 cold cranking. They said to get one that is a 1000 cranking amps. What battery would you all recommend?