[Teds89IROC]

so I'm getting 12.86 volts from the battery when the car is off and 14.3-14.6 when it's running. As soon as I put on the parking lights the volts drop to 13.3, put on the headlights and they drop to 12.8ish, put on the flashers in addition to the other lights and I'm at like 12.2. The battery was bought 2/05 reconditioned, could it be possible the battery isn't holding charge while accessories are on? I hear the alternator working harder while the flashers are on and my interior lights dim with the flashes. Any thoughts?