There are a number of ways to improve your laptop battery life. If you are working on your laptop and realize that you have to save up battery, here are a few tips to help you-

1. Reduce brightness: Reducing brightness may reduce your visibility slightly but a considerable amount of power can be saved by doing so. Make sure you dim the screen lights to save battery.
2. Defrag regularly - The faster your hard drive does its work – less demand you are going to put on the hard drive and your battery. Make your hard drive as efficient as possible by defragging it regularly. (But not while it’s on battery of course!) Mac OSX is better built to handle fragmentation so it may not be very applicable for Apple systems.
3. Add more RAM - This will allow you to process more with the memory your laptop has, rather than relying on virtual memory. Virtual memory results in hard drive use, and is much less power efficient. Note that adding more RAM will consume more energy, so this is most applicable if you do need to run memory intensive programs which actually require heavy usage of virtual memory.
4. Running multiple programs: Running multiple programs makes your computer work harder consuming more power. If you intent on saving battery it would be advisable to not multi-task.
5. Work from hard drive: instead of reading from the CD or DVD, try and work on the hard drive. The CD/DVD drivers consume more power.
6. Hibernation: a good way to save battery is to use the hibernate option instead of putting the laptop on standby.
7. Lower Graphics use: go low on the graphics, so it would be a good idea to stop gaming if you wish to save power.
8. Power options: make sure you switch to the power optimization option on your laptop.
9. Don’t multitask – Do one thing at a time when you’re on battery. Rather than working on a spreadsheet, letting your email client run in the background and listening to your latest set of MP3′s, set your mind to one thing only. If you don’t you’ll only drain out your batteries before anything gets completed!
10. Laptop temperature: your laptop works better in cooler temperature, make sure you give it proper ventilation and clean air sockets. Blocking the air passage builds up heat inside the laptop, increasing the temperature and consuming more energy.
11. External Device: reduce the use of external devices like flash drives, USB devices, external hard disks etc.
12. Battery care: make sure you don’t keep your battery for charging throughout. Once charged, use the battery supply. Also make sure not to drain out the battery completely.
13. Turn off speakers, Wi-Fi, Bluetooth etc to save power.