Just for informational purposes, all aircraft batteries are supposed to be Capacity tested yearly, again for what it's worth only the Concorde batteries are cap tested by the manufacturer, all other batteries are required to be cap tested prior to being placed into service
or they are not airworthy. Almost no aircraft batteries are capacity tested truth be known. Also at my last year renewal of my Inspection
Authorization Concorde gave a class on batteries, one thing in the class that stuck was their recommendation of replacing a battery every five years, even if it passed the capacity check, see the battery is the back up electrical
supply to run the aircraft radios, navigation gear
and some gyros in the event of an alternator
I would tell the OP that he has obviously done a very good job of maintaining his battery for it to still pass the capacity check after five years, but he might want to think about replacing the battery.