When Microsoft released Windows 7, one of their big selling points was the extra battery life it provided over Vista. The guys at LaptopMag.com found that it was indeed true, but only on full-sized notebooks. When it came to netbooks, it was a completely different story. The batteries of the netbooks actually drained faster than with XP.
They tested three netbooks, Toshiba mini NB205, ASUS Eee PC 1008HA, and the HP Mini 311, all with Windows 7 OS. They tested them with the “laptop battery test”, continuous web surfing over wi-fi, and found that each of them got a lot less battery time.
The results:           Win XP Battery Life         Win 7 Battery Life
Toshiba mini NB205         9:24         8:51
ASUS Eee PC 1008HA   5:40         4:43
HP Mini 311                   5:43           4:52
According to the tests, the netbooks average about 40 minutes less battery time with Windows 7, which is a big chunk of time. If you’re looking for the longest possible battery time on your netbook, it may not be wise to upgrade your XP system just yet.