Automotive Electrical Question

[NAPOTS]

I have what I think is a parasitic current draw on my boat that is slowly draining the battery.

I don't really have any experience troubleshooting electrical issues. I read that I should pull the negative cable off of the battery and measure the current between the cable and the negative terminal. I am measuring about 1.5 mA.

It doesn't seem to me that this would be a very significant current draw. If I am doing my math right that is about 1 Amp-Hour per month.

Right now I have it on a float charger.

Is there something else I should take a look at?

[alismith]

Not sure how to find the source of the current draw, but if you can't find it, I'd suggest putting a heavy-duty, inline cutoff switch in one of the cables coming off the battery. Turn it on when using using it, and turn it off when storing the boat.

[whiskeyman]

Does your boat have a clock?

[NAPOTS]

Does your boat have a clock?

Nope.

[davepool]

I had the same problem with my boat. Not a heavy power drain but if i let it sit for 4-6 weeks the batteries would drop to 11 volts. Had my son in law check it out and he couldn't find any thing, i broke down and took it to the Mercury dealer who ran a full check on the electrical system and said everything was fine but the clock and the on board battery charger were drawing off the battery all the time and that might be the issue. I had them install a power cut-off switch in the battery compartment.

As i was paying the $275 bill, i realized all i needed to do was disconnect the battery cables, but now i have this cool looking switch

[JTHunter]

You might have something electrical that is grounding out to the water. Or is this drain on your battery still occurring when it is out of the water?