I just got a new macbook air, it was working fine for a couple of days until yesterday. The battery seems to be stuck at 98% - or was. I rebooted because I started to lag, and was updating, then I unplugged it and plugged it back in, then it went down to 97%. What confuses me is the fact it had been plugged in (while shut off), for about 8 hours and it should have been charged by the time I got around to using it. When I right click on the battery icon, it says the computer is fully charged. Is there a way to fix this issue?