I've used my macbook today after it was fully charged at 10:30 AM. It's at 6% now and has about 30 minutes left. This means i used my macbook for 6,5 hours constantly. Using just Safari, Mail, Excel and MSN. So that's basically the 7 hours of non-stop internet which Apple communicates minus 30 minutes using Excel through the day. Which is totally acceptable.
So I don't know what happened with my Macbook yesterday evening and today's morning but it seems it's working properly (again).
Anyone else expierencing the same kind of 'problems'?