Turn off unused devices. Many laptops come with a switch or some way of turning off their wireless capabilities, such as wifi and bluetooth. Disable these because, believe it or not, they consume quite a good amount of power.

Unplug unnecessary devices. Many people use a usb or bluetooth mouse, not realizing that this draws power from your laptop. If you want to increase your battery life, you should unplug any external devices that you don't need.

Decrease hard drive activity. When your hard drive is running, it has a little disk inside it that spins. And the more it spins, the more you are going to see your battery power go down. To decrease hard drive activity, you should disable start-up items in the taskbar or anything that runs in the background (anti-virus, spyware, etc).

Another way to decrease your hard drive activity is to defragment your hard drive every so often. By doing this, you are cleaning up unnecessary files that may slow your computer down, causing the hard drive to spin more.

One last thing you can do is install more RAM (Random Access Memory) in your computer. This will speed up your system and will make it so your hard drive doesn't have to do as much work.

Condition the battery. Every-time you unplug your laptop for an hour and then plug it back in, the battery recognizes it and after a while believes this is how long it should last. Believe it or not, batteries do have memory, and if the battery is not conditioned every so often, you may see a significant decrease in your battery life. To cycle your battery, all you need to do is run your battery completely down, letting it shutoff by itself, let it recharge fully without unplugging it, and then it has been conditioned.