For the cost, replacing the battery after around six years is good policy. The enevitable dramatic reduction in capacity will be masked if its used regularly, starts easily or is kept on a charger - until the day it let's you down
Richard
2018 Roadster 3.7 1966 Land Rover S2a 88 2024 Royal Enfield Guerrilla 450 1945 Guzzi Airone