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Location: Mauston, Wisconsin | There are two distinct probabilities 1. The battery is bad or 2 the battery is just not getting fully charged. Your battery should be fully charged within 24 hrs. Seeing as you have a multimeter, I'd charge it for at least 24 hrs. Then take off the charger and let it set for 4-8 hours. Measure the battery voltage, if it's under 12.5V you might need a new battery.
But you also may want to check the output of your charger and your AC supply voltage. Sometimes with cheaper chargers if the AC voltage is low the charger cannot put out it's full rated DC voltage. This is not an uncommon problem at marina docks and/or if you use a long extension cord.
Look at the data plate on the charger it should have the DC output voltage listed. Your AC supply should be ~ 120V. Hook the charger up to a battery that measures full charge (~12.7V) turn on the charger. The voltage should go up to at least 13.5V to 14.4V.
A fully charged 12V battery should read ~12.7V at rest, thats after setting 4-8hours without being charged.
5 years or 100-200 deep discharges is about right on the average deep cycle battery.
Al |