Best way to troubleshoot shore power > batter charger?

[solecollector]

Hello all -

First off - love the community. Just great people on here with solid knowledge. Okay - not everyone but at least 99%

I purchased a 2006 Lagoon 440 that hasn't been used much. The genset has 200 hours and the engines 800. I brought the boat down to Key Largo and a few things decided to quit - one of them - charging the house batteries.

I have a Dolphin charger ('06 model) and the light is flashing green. Nothing else is lit up (none of the fault lights or boost). The breakers are on - shore power is on - but nothing is charging. When I turn the genet on - same thing - the house and engine batteries aren't getting charged (the house batteries are below 8). Now if I turn on the engine - the batteries charge - which I am doing right now.

I checked all of the breakers - didn't see any fuses except the big ones on the battery hookups - all looked good - but were hard to tell if those 100A's fried.

Any thoughts?

[Teknav]

Do a continuity test on each fuse. Make sure the power is OFF. Using your DMM, set to resistance (Greek Ohm Symbol), touch the poles of each fuse. If no reading on the meter, you have a bad fuse. Some DMM's have an activated continuity sound feature; a good fuse will continuously "beep".
Mauritz

[smac999]

turn your battery charger off. measure the voltage at all the positive outputs of the charger at the charger. (to the charger ground) you should get 12v at all of them (or 8v if that is where it is)

if you get 0. you have a blown fuse or disconnected cable. if you have 12v at all lines. and you turn the charger on it stays at the same voltage. then the charger is likely dead.

[sailinglegend]

Originally Posted by solecollector

...the house and engine batteries aren't getting charged (the house batteries are below 8). Now if I turn on the engine - the batteries charge.....

If the batteries are really below 8 volts then all or one of them is dead. Many chargers won't charge if the battery voltage is too low. If the engine will charge the batteries back to say 11.5 volts try then switching on the Dolphin and see if it starts charging.

[dohenyboy]

Right. I always keep a cheapo automobile charger on board, to charge the really low batteries until they are 11.5 v or so. Then the "smart" charger will work.
Look up battery equalization. Sometimes you can revive batteries that went dead due to underuse. Worth a try