Battery drain when battery switch is turned off.

[hmonarch]

I have a battery issue with my 2004 200 Sea Ray Select 5.0 MPI. My battery discharges when the boat is not in use and the battery switch is turned to the off position. This is a single battery set up and the switch is a simple on/off selector with only two positions; on or off. I have not wired anything directly wired to the battery so the system is stock as is as it came from the factory. The battery switch is factory installed. I did not add it to the boat. When in use everything runs without a problem. The battery charges as it should when I’m running the boat.

Some circuit is staying hot when the battery selector is turned off. I had always assumed that all the electrical circuits were disconnected when the battery switch is in the off position. I'm confident it is not a battery problem. The battery is new and I've had it checked. I even but another battery in but it discharged when I was not using the boat, too.

Can anyone tell me which circuits, if any, are designed to stay active when the battery switch is in off position? I’m guessing that the radio memory may stay active. And possibly the bilge pump. The bilge pump does have a float switch. I don’t have an electric system schematic to review. If I know which circuits are designed to draw current when switch is turned off I can set a meter at the battery and disconnect those circuits one by one to find the source of the problem.

 

[be_prepared]

Usually your bilge pump is live even with the switch off, also, there's often a small draw to your stereo to maintain memories. Some boats always have the blower switch live too, so you can run the blower without energizing anything else first.

 

[Lazy Daze]

There is a very good electrical schematic in your manual (the one that originally came with the boat). If you've misplaced that, you can download it from SR's website.

Assuming everything is factory... live circuits, with engine/batt switch off, would be: the bilge pump float switch, radio memory, and ECM (engine computer). Looking at the wires coming off your battery, you should be see some of this. Under normal circumstances, none of those should cause any issue and with a properly working system, even a few weeks of non-use will cause no issues with starting the engine.

Start by removing/inspecting/cleaning/reinstalling battery cables, battery switch cables, grounds, etc.

Next, use your DMM to do an amp draw test. I don't recall if the computer needs a certain amount of time to "go to sleep", but give it 15 minutes just to be sure. Note the amount of draw. If it's too high, start pulling fuses - one at a time - until you find the offending circuit.

 

[Little Ducky]

I bet it's your starter solenoid. See if you can hear it click once in a while when the engine is off. Starters should be hooked directly to the battery because it would cook any on/off switch when trying to start your engine.

 

[wayne0]

There is a very good electrical schematic in your manual (the one that originally came with the boat). If you've misplaced that, you can download it from SR's website.

Assuming everything is factory... live circuits, with engine/batt switch off, would be: the bilge pump float switch, radio memory, and ECM (engine computer). Looking at the wires coming off your battery, you should be see some of this. Under normal circumstances, none of those should cause any issue and with a properly working system, even a few weeks of non-use will cause no issues with starting the engine.

Start by removing/inspecting/cleaning/reinstalling battery cables, battery switch cables, grounds, etc.

Next, use your DMM to do an amp draw test. I don't recall if the computer needs a certain amount of time to "go to sleep", but give it 15 minutes just to be sure. Note the amount of draw. If it's too high, start pulling fuses - one at a time - until you find the offending circuit.

This!

 

[Espos4]

For a reference, modern automobiles with all their computer controlled items will see about 50-75 mA (milliamps) draw once everything goes to "sleep".

Something like an open door with the interior light on would show about 2 amps of current flow. That's like 2,000 mA.

I would suspect a boat like yours should be less than 50 mA with everything off.

 

[Bt Doctur]

Starters should be hooked directly to the battery because it would cook any on/off switch when trying to start your engine.

Nope, Old wives tale.Battery switches are designed for the starting load,