Problem w new humminbird 877

[Agent Andy]

I tried my new graph last night and it works great except when I hit the gas wide open the graph shuts off. when I increase the gas(for the motor) gradually there is no problem, only when I shove the gas forward real fast. The graph has its own battery. I checked the contacts and they are all ok.

[SpecialK]

Might be a voltage spike if your graph is hooked up to the same battery. I know the graph will shut down in low power situations and would imagine there is an over current shutdown as well.

[Agent Andy]

Thanks, but the graph is on a battery all by its self. The motor uses a different battery so there should be no spike????

[Dale Rueber]

I would look at connections on the battery and also make sure that the battery is not moving/tipping when you take off fast. If it is tipping the terminals could be contacting a metal surface briefly and shorting out. You may also need to check the wiring to make sure that there is no bare wire exposed that could move when you gas it.

[JohnMickish]

Change it to a different battery for a test, if the problem goes away you know it's the battery or the connections to the battery. It could be an internal battery problem. You can use a small battery from a Vexilar to test.

[Agent Andy]

Thanks 4 the great tips. All the connections are tight, no loose ones. The battery is the same one I used for my old 320 lowrance(piece of junk). I will try another battery, but wasn't aware of an internal battery. The graph is new. How do I check the internal one. I am leaving for Canada next Friday and would like to get this taken care of before then. Thanks again.

[JohnMickish]

I meant that the issue might be internal to the battery. Battery construction is such that it is possible under a certain lateral movement (acceleration in your case) that there could be an open connection inside the battery. Doubtfull but possible. A test battery would confirm or eliminate this.

[harvey lee]

I agree with mnfishingguy to get a test battery. If that does not do it, Birds CS would be a great place to contaqct.

[cheesehead]

what orientation is your battery? If it is sitting length of the battery paralell with the boat the plates could be moving and contacting each other under the force of the accelleratio. this is a common problem with racing cars.

[cheesehead]

what orientation is your battery? If it is sitting length of the battery paralell with the boat the plates could be moving and contacting each other under the force of the accelleratio. this is a common problem with racing cars.

[Ed Carlson]

You said the battery is separate, but is it hooked to charge from the boat motor as well?

If so, it may be not regulating voltage properly. Causing a surge above tolerance and shutting the unit down to protect itself.

An in-line voltage regulator would solve this. Better yet check the output from the motor to see if it is overcharging.

If that battery is completely isolated from any other circuit, then it must be a bad cell as many have suggested.

[Agent Andy]

The battery isn't hooked up to the motor at all. I need to charge the battery. This is the same battery I used with my old graph and never had a problem before. I will be leaving Friday for Canada and I will just have to start out slow until I can figure it out. Thanks.

[Ed Carlson]

OK...well that's not it then.

Unless the tilt of the rise of the boat as you go on plain at a higher speed is somehow stretching a already tight fuse link or connection to the sonar unit....or is vibrating enough to break or weaning the circuit sufficiently for the voltage to drop and shut it down...if not...well....I'm stumped?

I still suggest you try another battery, and see if it does the same thing.

[Agent Andy]

I am charging another battery and will install it before I go Canada. That will be the first chance I will have to test the theory. Hope it works.