Just because a battery shows 12v with a voltmeter does not mean it has full capacity to start a vehicle. The only way to test a battery is with a load tester.
A motorcycle battery is good for 2 to 3 years if maintained well (kept on a battery tender when not in use and never let to fully discharge) Some better quality ones will last 5 years or more.
A motorcycle battery is good for 2 to 3 years if maintained well (kept on a battery tender when not in use and never let to fully discharge) Some better quality ones will last 5 years or more.