Battery Draining

[Matt C]

What might cause my Cranking Battery to go dead after 5 days of no use?

I have no accessories on, main power is off. New battery/boat this winter and I have not had an issue until this last month, it has happened twice now. I charged it up fully after the last time, went out for an hour or so, no issues, was going to head out this am, tried to lift the motor, and she was very weak.

[Jeremy airjer W]

The first thing I would do is disconnect everything from the battery, charge it up, make sure it is charged, then check it again in the same time frame that it has been discharging. if its dead or weak than Its likely to be an internal draw in the battery.

Its not real common but I have seen several automotive application with this problem over the years.

If it holds its charge after its been disconnected from everything than there is a draw in the system.

[Matt C]

airjer - thanks! She's fully charged now and I'll see what happens over night tonight. Hope it hold cause there are walleyes waiting for my lures tomorrow am.

[Bigbartguy]

fyi - we had a current leak in our boat - the Merc low oil warning sensor was bad

[marine_man]

Have you added any powered accessories in the last two months? A GPS receiver that is not switched will draw a battery down over time pretty easily.

marine_man

[Jeremy airjer W]

Heres a funny story. Took the boat out for a day of fishing, got home put it in the garage like usually. Went to may the lawn and I hear this clicking noise near the back of the boat. Didn't really think anything of it. Two days later I'm getting some stuff of the shelf behind the boat and I still here this clicking noise. I look all over I can't figure it out. Go to leave for a five day camping fishing adventure and figured out I had left my depth finder on.

[mpester]

Do you have a Lowrance depth finder/GPS? I installed a unit this year and after my cranking battery was dead a couple of times, I learned that the GPS antenna has power to it even when the unit is off. That was enough to kill the battery. I attached an alligator clip to the power cord and unhook it at the end of the day. Someone who is better at installing electronics than me would install a switch leading to the depth finder/GPS.

[BobT]

When you install accessories like GPS, sonar, etc. it's a good idea to supply them from the accessory switch if you have one. This way you can shut of the switch when you are not using the boat and it kills power to all accessories. You don't have to wonder if any of them are drawing power from your battery while not in use.

Bob

[Matt C]

All my accessories shut down when turning the 'main' power switch down.

I did let the battery sit with the positive line unhooked, and she went dead again.

So, shes going in for a warranty replacement.