Keeping your laptop screen brightly illuminated burns battery power. Especially when you're working in an application that presents a light background, such as word-processing software, you can turn down the brightness without inconveniencing yourself. Check the documentation for your specific notebook system, and use its keyboard shortcut or productivity tool to adjust your screen. Contrary to popular belief, screen savers that involve complex graphics and animation not only don't save power, but actually may use more energy than your undimmed display.
Tools and Tasks
Windows users often run surprisingly large numbers of background tools and tasks that eat battery power. Check the notification bar at the bottom right corner of your screen for the icons representing your current complement of tools. Reveal any hidden items by clicking on the up arrow at the end of the bar, and hold your cursor over any that you don't recognize to reveal their names under your pointer. Turn off anything that isn't essential -- especially utilities of questionable value that shipped with your system -- and limit the numbers of scheduled tasks you run.
When you activate Windows' power management features, you can choose to dim or turn off your screen and put your computer into a low-power sleep mode after it's been inactive for amounts of time you specify. Access these settings from the Start menu by bringing up the Control Panel. Once you activate power management, you can walk away from your computer and know that it will step down into power-saving mode. Remember that screen savers, open networked files, active network and online processes, and any fingertip contact on your touchpad or keyboard constitute activity, and will prevent the computer from going into sleep mode.
If you're not using your laptop's wireless capabilities, turn them off. Depending on your hardware, you can remove your Wi-Fi card or unplug your USB Wi-Fi interface after checking for networked drives or files, ongoing file downloads from websites and any other incomplete wireless-dependent tasks. On some laptops, you can turn off the wireless connection using software settings. Check the documentation for your laptop and any add-on wireless interfaces to determine how and where to turn off Wi-Fi.
How you charge and discharge your battery can affect how long it holds a charge. These strategies depend on the type of battery you have. Older laptops with nickel-metal hydride, or NiMH, battery packs benefit from periodic discharge/recharge cycles. Every three months, run your system off its battery until it shuts down, then recharge the battery completely. However, the same strategy hurts more modern lithium-ion batteries, which you should never discharge completely, so verify which type you have. Battery-use strategies also vary by battery type. Unlike lithium-ion cells, NiMH batteries fall prey to the memory effect, which can stop you from recharging them fully if you've drained them partially and recharged them. Avoid repeated short-charge cycles with NiMH cells. Conversely, put your lithium-ion-powered system on electrical power as soon as you can, regardless of how much battery life is left.