Macbook Battery

my macbook only 1 month old. It is a white macbook, mid 2010 model. Apple says it has 10 hours battery. But my macbook can only work around 4,5 hours. Battery has only 12 cycles,
normally I do only web browsing and play music. I work with low screen brightness too. Why my macbook can't work 9,10 hours ???

Ask Apple. If you feel you are having a problem...return the computer to Apple for repair or replacement.

- Nick

Battery life will depend on workload, processing, disk usage etc. That being said, I rolled back from 10.7 to 10.6 because the 10.7 install halved my battery life. In fact, every one in my family with a portable has complained about it.

That being said, I agree with pigoo. Just go into that conversation prepared for them to troublesoot the problem before taking any replacement actions