Tips on how to extend your notebook's battery life
Running out of battery power in the midst of a crucial project is a common fear among mobile computer users. If you've ever had to rush off in search of power so you could finish an important presentation, you'll appreciate knowing how to get the most out of your notebook battery.
Batteries for laptops come in three main types: nickel cadmium (NiCad), nickel metal hydride (NiMH), and lithium ion. Each of these batteries is rechargeable with an AC adaptor. In most cases, it will give you between two and four hours of computer use, depending on a number of factors.
Here's what you can do to extend your battery's life.
- Keep track of how much power is left in your battery to avoid unexpected disasters. Moving your mouse over the battery-shaped icon in your Task Bar will show you the percentage of battery power still available.
- Reduce the brightness of the screen to the minimum readable level. Many notebook models have keyboard buttons that allow you to do this easily, or you can use the slider in the Display Control Panel.
- Put your computer to sleep whenever you are not actively using it. Most notebooks come with built-in, automatic sleep features, but you should get into the habit of doing it manually whenever you step away. Sleep mode, sometimes called "Suspend," shuts off monitor, hard disk, and processor, while preserving everything in RAM. When you return and activate your computer, usually with a mouse or keyboard movement, you can resume working just where you left off.
- Sleep mode saves energy, but it will eventually run down your battery if you leave your computer indefinitely in this condition. Worse, you risk losing everything saved in RAM if your battery dies. If you plan on being away from your computer for more than an hour, try the "Suspend to Disk" or "Hibernate" mode. These save the contents of RAM to your hard disk before shutting down. While slower to activate, these save more power than sleep mode and eliminate the risk of losing any important data.
- Remove peripherals when not in use. External hard drives, CD-ROMs, Zip drives, modems, and other peripheral devices can draw power from your battery even when they are not in active use. Disconnect them when you have finished using them.
- Reduce the speed of your processor. The faster your computer works, the more quickly it uses up the supply of power. By cutting down on processor speed, you can extend the charge of your battery. Methods to reduce processor speed vary from model to model, and your manual should provide instructions for doing so.
- Deplete the charge on your battery completely before recharging. While memory effects in modern batteries are much reduced from what they were a few years ago, you will still suffer a loss in the charge a battery will hold if it is not completely drained first, resulting in a shorter battery life.
- Consider buying an extra battery. This way you can charge one while the other is in use, and be confident of never running out of power at a critical moment. Some notebooks, including models in the HP Omnibook and Compaq Presario lines, have an alkaline battery pack available, which provide extra security for times when no power outlet is available.
- When you get a new battery, or if you're using a battery that's been idle for a few months, charge and drain it three times. This fully activates the battery chemicals that may have become lazy after a long rest.