You will get better battery life if you use the drivers from Boot Camp 3.0 on the Snow Leopard disk. On my MacBook Pro unibody 2009, I get life in the 4-5 hours range with the NVidia driver Apple supplies with Snow Leopard Boot Camp 3.0 and 2-2.5 hours with the latest driver available from NVidia.com.
Update: There are newer official NVidia OEM compatiblie drivers available than the ones bundled with Boot Camp 3.0. These work without hacking the INFs. Laptop Video To Go has archived the 186.03 x86 and x64 drivers from NVidia's site.
- http://www.laptopvideo2go.com/drivers/win7x32/186.03/disclaimer
- http://www.laptopvideo2go.com/drivers/win7x64/186.03/disclaimer
Just make sure NVAO.inf from additional_infs.zip is extracted and the 186.03 driver will install and work.
There are also more recent BETA quality drivers archived at laptop video to go.