Battery And Boat Wiring

[David Unnerstall]

Make sure all of the connections are clean. It sounds like something is creating restistance in the Humminbird circuit.

[mixermarkb]

Take a look at wire gauge and connections on the hummingbird. I had a similar issue with a lowrance HDS that I solved by making a better connection and getting rid of my sloppy wiring

[GNSfishing]

Thanks for the good information, everybody. I pulled the "bad" battery this morning and took it to the auto parts store where I get Delco Voyager marine batteries. I figured I'd replace it with a cranking battery in the same Delco series. They tested the battery and it was fine - both for voltage and cranking power, so I don't know what's going on with that depth finder turning itself off when I start the main motor.

Maybe it's more of a depth finder issue. It's a Humminbird 597, and it doesn't exactly turn itself "off" when the motor is started. Usually it goes into some super-faint mode where you can hardly see the screen but it is still sort of "on". None of the buttons work when it's in that condition, and the only cure is to remove the depth finder fron the console, re-attach it, then press buttons to turn it on. Does anyone have any ideas about that?

I'm charging both batteries up, going fishing tomorrow. Since the batteries are identical I'm switching them - maybe that will make a difference.

Remove the depth finder from the trolling motor batteries. These electronics do not like low voltage and/or voltage spikes. A brand new battery on the trolling motor will run the electronics until it is starting to run down during a full day of use and then you will start to have problems with the electronics as the voltage gets down when you use the trolling motor. The trolling motor will begin to give low voltage spikes as you use it starting and stopping moving the boat. Solve the voltage problem with the electronics by installing a larger engine starting battery and run at least 12 gauge positive and negative wires (also be sure to install a fuse) to the front of the boat and your problems will disappear.

[Craig]

You should be using a marine starting battery for the motor and a deep cycle marine battery for the trolling motor. That deep cycle battery will not give you the amps for starting like a starting battery. About connectios and wiring very good advice.