Phantom electrical leak

[tuggin aweigh]

I have a phantom electrical leak on the house and possibly on the engine battery. Tuggin Aweigh is an early model R25. Has anyone encountered the same problem? Do you have any suggestions on locating the culprit. We have auto-pilot but the over head module is turned off.

A leak is evident even though all switches (main, engine and house) are in the off position. The leak is enough that it will drain the battery if left off the charger.

Thanks.
Tuggin Aweigh

 

[Stella Karuna]

I also am having a 0.5 AH leak. While not appearing to be significant, over one week it does drain the batteries. I have a 2011 25SC.

cheers Bill

 

[sidetrack]

The leak may be the float switch on the engine sump. The float would not turn off sometimes.... This meant you could test everything and all would be ok... and then the sump would engage, via the float switch, and not turn off. The problem turned out to be caused by a back-wash valve that was sticking and not letting water out of the hose and hense keeping the float activated and the sump running and drained the batterry. I fixed it by taking the valve apart and shaving some of it off so that it could not stick...... This was a hard item to diagnose... so I hope that it is your problem as the fix is easy.

 

[lbrown]

I had the elect drain problem this spring also. Was able to trace it to the CO detector in which heavy corrison had formed causing a short. Check this by unpluging the unit and see if drain is stopped.--Leonard

 

[Levitation]

Along with the above items mentioned check for parasitic draw on the thruster(s)... My rear thruster leaks a bit (small) that drains the battery over time...

 

[Levitation]

Ugggh, fat fingered that...
Was adding, that you may need to remove the cover from the + bus and disconnect all connections and test them one at a time to find the branch that has the parasitic leak - then go hunt for the item on that line... Remember to suspect the charger itself and the Blue Sea combiner relays...

 

[rustednail]

Here's something I have seen on cars, boats and even airplanes; electrolyte spilled/leaked/weeped on top of the battery. Electrolyte is conductive and can drain the battery over time. A half amp draw is kinda high for this kind of problem though, but it is not out of the realm of possibility.

This is also an easy fix, simply clean the top of the battery. The cause, well, might not be so easy to find. If the batteries were just serviced, then spillage could be the cause. Overcharging from either the alternator or the onboard charger could cause some gassing and moisture accumlulation. If either charging source is over 14.4 volts then over charging is a possibility.

If your batteries are clean and you have an amp meter indicating the leak, you can remove the fuses or pull the circuit breakers one at a time to find the circuit that is leaking. I'm not sure about your 25, but my 21EC's bilge pump is fused at the battery for the automatic function(float switch).

Way back when i was a teenager, I had a truck that had a light in the glove box. Well, the glove box door got something stuck in it to keep it from closing all the way and prevented the door from actuating the switch. The light remained on and thus drained my battery. Of course, it was out of sight and went unnoticed for weeks. A battery later, i accidently found my owners manual was keeping the door from closing all the way.

Are all the lights off on your boat? What about the one in "the cave"?

This is very rare, but it is possible for a diode in the alternator's rectifier to have gone bad and allow current to flow back through the alternator. The only way to test this is to dissassemble the alternator and test each diode indivually.

I hope this has been some help. Good luck with troubleshooting this. Hope its an easy fix

--Bri

 

[Toodles]

I, (with the help of competent mechanics) had the whole electrical system changed, starting with having a true "smart charger" installed that reads the individual batteries. Then all the extra hooked up parasite wires, which are continously drawing down the batteries have been removed. There is no need for all these wires to slowly draw down these batteries for no good reason like the computer for the Cummins, thrusters, radio etc. New 1000 amp AGM batteries, (yes 4 , 32 cell) and a galvanic isolator, LED lights, and another switch to turn off all electrical power for the chance that there still is any draw when I turn off the batteris.
Had this work done since the house batteries had a draw which pulled down the house batteries even with everything turned off and then the old charger did up "cooking" the other batteries as it could not distinguish which batteries needed the charge, last season I added 2.5 gallons of destilled water during the six months that I used the boat. Now I can tie three batteries for house if I like by using a switch and then separate the thrusters when under way.