New battery discharges quickly

[timberxx]

New marine battery discharges without any known use(all electrical switches turned of) after few hours or minutes. I have a simple boat with only running lights, horn, and bilge pump in addition to 55hp o/b. I fiddled with the bilge pump recently before problem started, then replaced in-line fuse link from b. pump to battery. Pump "ground" since bought used has been merely screwed into aluminum of boat itself.<br /><br />Anybody have diagnosis/testing/repair suggestions? thanks

 

[Ralph 123]

Re: New battery discharges quickly

You could just have a bad battery or it just hasn't been fully charged and your alternator hasn't charged it up all the way.<br /><br />Pull the battery and put it on a charger and see if you can fully charge it, you can also take it to a place like autozone or maybe even Sears and have it tested.<br /><br />If the battery is good and fully charged and still discharges quickly, you have a short somewhere. Try the battery first, if it still happens post again and we can talk about some ways to track it down.

 

[timberxx]

Re: New battery discharges quickly

Thanks Ralph. The battery seems OK: I have recharged it myself 3 times due to this problem of unknown discharging and each time I connect it to the charger(after noting it is dead/not staring motor or lighting lights) the charger amp meter starts out at just under @ 10 when I start the re- charging and ends at just above @ 0 right before I turn charger off. The battery then works to light lights, sound horn, run bilge pump, and start engine. I have only run the engine about 2 minutes since the problem started. And I notice the dead battery when I return to the boat and try the lights, etc. I have not been knowingly operating anything when the it stops working.<br /><br />An added point: I note lots of 1/4-3/8" pieces of styrofoam in bilge water well from under floor. I suspected bilge pump clog and maybe float switch held up by the styro bits, but haven't heard it running. After last fiddling with the pump and replacing the mechinally sloppy in-line fuse link from positive battery terminal to pump, the pump did seem to work fine.<br /><br />Hope that helps you narrow the possible problem. Looking forward to your thoughts.

 

[Ralph 123]

Re: New battery discharges quickly

The best way to find the short will be to remove the negative wire from the bat and insert a curretn meter or even a light. Start breaking the circuits one by one by pulling fuses or physically disconneting Pos wire. When the light goes out or current draw stops, you have found the circuit with the short. Then you have to look at why the circuit is shorting. Is there a fray on the pos wire touching grnd? Is it a bad ellement in the accessory?, etc. etc. Once you find the bad circuit you will know what to do.<br /><br />If I had to guess, it would be the bilge circuit. Either the pumps is no good, The float switch is stuck on and the pumps is constantly running, etc. That would be the first circuit I'd look at.