You May Think Your Charger/Converter Is Bad But Maybe Not

[ttmott]

The original installation of the wiring from the Bow Thruster battery charger to the battery wiring had a poorly done crimp/disconnect causing that connection to get hot and eventually fail preventing the batteries from being charged.

I hardly ever use the bow thruster but I test it every month. It didn't work at all when I tested it last week; the main power solenoid wouldn't even operate.
So the batteries (2 in series, 24 volt) discharged to 11.5 volts (about 6 volts each) - dead.
Ok, so I fixed the charger wiring issue and reconnected the charger, a Sterling 24 volt 20 amp unit, and nothing. Let it charge over-night and the next morning - nothing.

As it ends up all modern battery chargers will not turn on unless they can sense an appropriate resistance which indicates the battery has a base charge above a certain level. It prevents the charger from being damaged due to an open circuit.
So, if you end up in a situation like this - connect the dead battery to a good battery and allow it to absorb the minimum charge to around 10 volts then connect to the charger and start the charging.
BTW - I have a perfectly good Sterling 24 volt charger if anyone needs one....
Tom

 

[SCORPIO]

I've got a Promariner 40 on my 3 battery bank and last fall I got a 911 from the marina that an alarm was blaring on my boat. Thinking it was my high water alarm, I drove 3 hours to find out it was the battery charger monitor panel alarming. One of my 3 batteries had gone totally dead (4 volts) and caused the charger to go off on over temperature, triggering the alarm. Needless to say I was relieved the boat wasn't taking on water, but I did find out that newer chargers won't charge a dead battery. Lesson learned.