1. If you regularly defrag the hard disk, it will make your hard drive work less that puts lesser load on your laptop battery and your laptop battery lasts quite longer.
2. You must monitor the usage of resources through Windows Task Manager.
3. Most of external devices like USBs serve as the biggest battery power drainer. 
4. If you have watched some DVD or CD, don’t leave it anymore in DVD/CD Drives, as they can suck battery power like a swab.
5. Don’t use DVD external drives when you are running your laptop on batteries.
6. Another big sink of some laptop is its LCD screen, Use Function key toggles to standardize the brightness at the level you can bear.
7. You can maximize the battery life of your laptop by muting the speakers and to avoid using multimedia software.
8. It’s better not to put any screensaver to give little boost to your laptop battery life.
9. Try to get acquainted with the given Power Options that are available in the Control Panel, familiarity with these options can help you a lot to save considerable power for your laptop.
10. If you are working on lots of programs when you are on the battery it’s the surest way to drain you laptop juice.

via technologygear