Pigtail discharging battery?

[charlg]

Every time I plug in the pigtail and use the 110V from the house through an extension cord, it discharges the starboard battery completely. The main panel was on and the gauge showed it was charging, and the battery switches were off.

This happened last year and I thought the battery was no good. By the time I replaced the battery, I was in the water and shore power at the dock worked fine. Then when it happened this year, it's got to be the pigtail.

What would cause this?

 

[2000SEARAY280SS]

I have basically the same boat. Check the AC cables going to the boat for continuity with the cable disconnected from the house and the boat. If the ground wire is broken off on the extension cable some stray AC voltage may be causing some issues but I really do not think this is it but a good practice none the less.

Have you checked the voltage at the battery when the charger is on? You may think you are charging it but the charge cable my be bad or corroded.

While you are on the hard the battery charger does all of the charging and while you boat the alternator is doing it. Not exactly rocket science here.

More than likely you have a stray DC load bring it down. My mercathode system is the only non switched thing on my starboard battery.

An easy way to check is with a light bulb. If you have a dc light bulb in a socket with two wires do this. Disconnect the negative battery cable at the battery put the light in between the negative post of the battery and the battery cable and if it lights up you have a current draw on the battery.

The brighter the light the higher the current.

My money is on the charger circuit

 

[Crushin It]

Every time I plug in the pigtail and use the 110V from the house through an extension cord, it discharges the starboard battery completely. The main panel was on and the gauge showed it was charging, and the battery switches were off.

I have the same thing going on. Did you figure it out? I'm gonna check some of the things Mike suggested.

 

[charlg]

Yes, we figured it out. The charger was not getting power from the main panel. It was a loose wire. So the batteries were not getting charged at all. Still don't know why there was such a big drain on the starboard battery, but everything is good now.

 

[Crushin It]

Let me ask...
What loose wire? One that should not have come loose or one that came loose during a winterizing process?

 

[charlg]

One that must of come loose while I was installing a new stereo, amp, and remote. I took the main panel off during installation and must have done something. That is what a friend (an electrician) said he had found.

 

[Crushin It]

OK Thanks.