[firstlight]

2006 36' open qsb 380
I have five agm batteries  three designated for the engines and two for the house and generator.
My house side batteries are two years old and lately after vessel sits at anchor for three or four hours the batteries go dead.
I load tested them after fully charged and they read ok.
i have the cabin refrig, the cockpit refrig. and electronics on for the period of time while at anchor, nothing more that I have used or the last five years? 
Any thoughts or similar problem? thanks

[trit21]

When you say you tested them, how did you test them? Volt meter ? Load tester?

[tyresmoker]

You sure about your configuration?
I have three house (starboard-front) and two engine (port rear) in my 3500/370 Cummins.

[firstlight]

I did a load test only.
Two batteries port side house
Three starboard side engines 
Thanks

[jclark003]

I've seen batteries that fall off quickly yet can still pass a load test when fully charged. I would first check that your charging system is operating correctly and configured for type AGM batteries. Improper charge rate/voltage can result in premature battery failure. After that an amp meter shoukd tell you if the problem is with the batteries or if you are drawing more current than expected.

Good luck

[bigboatben]

I did a load test only.
Two batteries port side house
Three starboard side engines 
Thanks

I’m pretty sure the two portside batteries are your starting batteries and the 3 starboard are House. Just sold two of these in the last couple months. Replaced battery’s on both and added a solar setup to one. Both had 3 house batteries to starboard. On one of them we went to mastervolt SL 200s for almost 600 Ah. Fits like a charm but each battery cost $700.00.
It sounds like something in the boat is really sucking down the juice. I’ve heard of refrigerators doing this towards the end of there useful life. Maybe try running the boat on D/C Power only but leave off one D/C powered item each time you test?


Sent from my iPhone using Tapatalk

[firstlight]

I'm trying to identify two orange wires connected to the house batteries with twenty amp fuses.  When the battery switch is off theses wires are hot, I first thought they were for the bilge pumps but they've are not. Thanks

[trit21]

I believe those wires are the sense wires that go the external alternator regulators, I have the same wire colors with fuses as well. 

I'm trying to identify two orange wires connected to the house batteries with twenty amp fuses.  When the battery switch is off theses wires are hot, I first thought they were for the bilge pumps but they've are not. Thanks

[firstlight]

I'm experiencing a excess battery draw
Are those wires supposed to be hot. When I connect them to the battery with battery switch off I get a spark?

[rcwiegand]

I have the same issue with a 2004 35 open. I did zero in on the two in cabin Carbon Monoxide alarms being hard wired and drawing ~2 amps each. Not certain if this is the final culprit-I disconnected them from power to see. I will check later this week. Pls keep me informed and I will do the same.