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The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
I have two banks of batteries, Batt1 and Batt2. This year for the first time Batt2 was absolutely totally dead. The battery charger won't charge it, the indicator light says the battery is too low to charge. Further, there is a big Battery Selector switch,"Off";"Batt1";"Both";"Batt2".
In the Batt1 position, I get a little juice, Both gives me the same, and Batt2 is dead. Here's the strange wrinkle. In the "Off" position, I'm getting power to the DC circuit. I can turn the lights on. What The Heck ??? This never happened before. All the time I've owned the boat, off means OFF. I'm thinking the selector switch has failed shorted out somehow over the winter. Does anyone have any thoughts ? Other than Salt Water and Electrical components don't play well together. Thanks in advance.
"Lady E" 1986 Catalina 25: Fin Keel, Standard Rig, Inboard M12 Diesel, Sail No. 5339 Sailing out of Norwalk Cove Marina, Connecticut
Yup--disconnect the batteries at their + terminals and replace the switch before battery 2 kills battery 1.
Dave Bristle Association "Port Captain" for Mystic/Stonington CT PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired), Now on Eastern 27 $+!nkp*+ Sarge
Thanks. I was pretty sure it's the switch. I'll replace it. The batteries are now 10 years old. I should replace them also. I'm just concerned that the switch may not be the problem, that there is another issue I may not be diagnosing.
"Lady E" 1986 Catalina 25: Fin Keel, Standard Rig, Inboard M12 Diesel, Sail No. 5339 Sailing out of Norwalk Cove Marina, Connecticut
Two suggestions off the top of my head: 1. Have you checked the water level in the batteries, assuming they’re traditional wet cell lead acid batteries. If you replace the DISTILLED WATER in the battery, you may be able to recharge it. 2. Disconnect the switch and run off your “good” battery for now. Check each battery’s connections for corrosion while you’re at it. Using your ohmmeter, test out your four-position switch. Looking at the back, you should have three lugs: battery A, battery B and Panel. OFF - you should have no connection among the lugs A - battery A should be connected to panel B - battery B should be connected to panel BOTH - all three lugs should be connected By connected I mean about 0.2-0.5 ohms max. If you measure 10 or more ohms anywhere you need a new switch.
Edit: oh wait, 10 year old batteries are at about the end of their useful lifetimes.
Bruce Ross Passage ~ SR-FK ~ C25 #5032 Port Captain — Milford, CT
In light of your last comment which came in coincident with mine, replacing 10 year old batteries would be a great idea.
I’d still try to get to the bottom of the battery switch. Being able to turn on your lights when the power is off is pretty mysterious...
On Passage, all my house DC circuits turn off with the main battery switch. Only the engine starter + alternator circuit remains connected at all times. Both circuits are fused separately at the battery terminal for fire safety.
Sometimes, depending on how some boats are wired, some house circuits are not shut off via the battery switch. VHF radios, cigarette lighter outlets and bilge pumps are common examples. While uncommon, sometimes these circuits can inadvertently “back feed” the panel even if the house switch is off.
Is it possible the lights are on a non-switched circuit, or were backfed somehow? LEDs don’t require much current so this is not beyond the realm of possibilities.
Bruce Ross Passage ~ SR-FK ~ C25 #5032 Port Captain — Milford, CT
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.