Humminbird 1199 and dead battery

I run a Humminbird 1199 on my cranking battery and it keeps killing it after the motor is off for a very short amount of time. Now the battery is 6 years old so I am assuming my problem is the old battery but it starts the boat up with no problem. So I am just making sure that if I get a new cranking battery that I will be able to run this unit for long periods of time with the motor off. How long should I be able to run the 1199 before starting the main motor up?

Tough to say what’s going on without more information. Do you have a voltmeter? It would be interesting to see what the voltage is on that battery. When the motor is running it should be around 14.4 volts. Just sitting there it should be around 12.6 volts. It will drop some when you’re turning the motor over but then bounce back. A depth finder should run forever on a battery that size, think about how long the little 7AH batteries ice fishermen use will last. The only thing we know for sure is that your battery is 6 years old, and that’s getting old for a battery.

For the time being I’d check the water level in the battery and clean up all the connections with a wire brush or sandpaper until they’re all shiny, and also make sure the battery is charged up.

SR

Do you charge your starting battery between trips?

Depends on the motor requirements for starting.
I emailed Mercury to get my minimum voltage for my 90 HP 4 Stroke.
They responded in 2 hours with 11.5 volts.
I then set this as the minimum voltage warning on my Humminird 1198.
When it chimes, I start the engine.

Replace your battery. Longest i’ve ran mine is for 3 days with short runs inbetween.

My batteries are also getting old ~3-4yrs. When i crank my motor i can get low voltage warning towards the end of a long weekend.

First off, replace that battery with a new group 31 deep cycle if you have the room. 6 years of use from a boat battery is along time. Starting and duel purpose batteries just don’t have what it takes to run bilge pumps, VHS radio, stereo, live well, 2-3 depth finders. Second, is the depth finder wired into a fuse box, or is it hard wired directly to the battery. It should be directly wired to the battery with a fuse at the battery. Hard wiring the depth finder to the battery will cure the depth finder from shutting down when you start the motor when the battery starts to get old and loose volts. A on/off switch is also recommended between the depth finder and the battery. I don’t know about the newer units with internal antennas, but the external antennas on older units did draw power when the unit was turned off and a on/off switch was recommended. I have left both units on all night with the boat on the lift and it started without a problem in the morning.

Thanks for all the input guys! I am for sure going to replace the battery. Puddlepounder, how difficult is it to do the wiring myself straight to the battery and adding the on/off switch?

For me it was very easy and I am no electrician by any means. Depending on the boat you have, there are wire runs that go from the dash to the battery. It is as simple as pushing a fish tape through and pulling the wires back through. The toggle switches I use are the ones that light up when in the on position. You will need to drill a hole in the dash for the switch. Wires from the depth finder go to the switch and the same with the wires from the battery. Don’t forget to put a fuse on the positive wire at the battery. It was trial and error to figure out what wires go on which connections of the switch. A quick google search of a simple wiring diagram will point you in the right direction. I solder all connections onto the wires, first crimp them on, then solder.

You should set the minimum voltage alarm on the Humminbird as well.
Even a brand new battery will discharge under heavy usage.
When the battery voltage drops to the minimum starting voltage for the motor
it will sound an alarm.
Then you start the motor and recharge the battery.