I just got a 12" refurb from Apple ...works great when plugged in to the AC. I charged the battery to 100% and was going to condition the battery by running only on the battery 'til it ran out of power. When I unplugged the AC from the PB it shut down abruptly. When I tried to power on it did so for about a second then quit. Is this a known issue with a well-known (but not by me) fix or does this sound like I got a bum battery? If no easy fix is know I'll be calling Apple for a replacement ...figure it's easier to try here first. Thanks for your help!