Modern smart chargers have 3 or 4 stages of charging. LEDs on the charger should indicate what step a charger is on. It’s normal for a smart charger to continue its last stage indefinitely, with an LED lit to match.
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This is a good thing. That last “maintenance” stage is designed to keep your battery healthy over weeks or months of storage, compensating for self-discharge, which otherwise can severely limit the life of a batt. It can be the difference between 2 years or 10 years of service... but there are other factors. Basically, you want to limit or eliminate resting in a deep discharge condition... and a normal discharge will turn into a deep discharge and continue to get deeper over time. Over enough time, a fully charged batt will go into deep discharge. Colder temps speed up this process... as in typical winter storage. Plug that trailer in!
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This is kind of inconvenient for the stock CI charger, as it’s mounted down between the tanks where it’s hard to see what LED is lit and if there is a label next to it. IIRC, the LED status lights aren’t covered in the CI manual.
If you can figure out which charger you have (there has been at least one change of brand), you can download the charger manual from the manufacturer’s website for reference on what the LEDs indicate.