How to treat your battery right

For on-the-go computing, your battery is your best friend. Knowing how it likes to be treated is the first step to keeping both of you happy.

• Keep battery contacts clean. Battery contacts can get dirty or corroded over time, reducing the effective delivery of power. With your mobile PC turned off and unplugged from its external power source, remove the battery. Use a cotton swab dampened with rubbing alcohol to wipe the metal contacts on the battery and inside the device. Allow them to dry completely before reinstalling the battery and reconnecting to a power source. Repeat this procedure every two to three months.

• Charge your battery correctly. When you're on the road, be sure to carry a power cord and plug your computer in whenever you have the chance. Unlike the older-generation rechargeable batteries like nickel-based (NiMH) batteries (see next paragraph), modern lithium ion batteries can be partially discharged and recharged repeatedly with no harmful effects, but you should avoid fully discharging lithium ion batteries. Consult your owner’s manual for more specific tips on charging, and never use an AC adapter (power cord) or battery charger not approved by your device’s manufacturer.

• Completely drain nickel-based batteries periodically. If you're using an older laptop (at least three years old) with a nickel-metal hydride (NiMH) battery, be sure to completely drain it and recharge it (every one to three months—consult your owner’s manual) to ensure that it will hold a full charge. (Most newer mobile PCs use lithium ion batteries, which don't need to be drained to maximize their capacity.) To drain a NiMH battery, simply turn on your computer, unplug it from its external power source, and let the computer run. To speed things up, you could start several applications, turn the screen brightness to its highest level, and ignore all of the great power-saving strategies below. After the power is completely drained, recharge the battery fully. This may take up to 12 hours.

• Cool it. Your mobile computer generates heat, and higher operating temperatures reduce your device’s efficiency, which in turn demands more battery power and can shorten battery life. Make sure that your computer can “breathe”: Don’t let clothing, lint, or other obstructions block the cooling vents. See How to clean your computer for more tips on keeping your computer spotless and running smoothly.

• Carry a spare. Buying an extra battery is a good investment for your peace of mind. Battery prices vary widely. You can significantly increase the power available to you if you're willing to splurge a little. Contact the manufacturer of your mobile PC to find a replacement battery, or find here.

• Store it properly. If you don’t expect to use your mobile computer for a week or more, it’s a good idea to store the battery, discharged to about 40 percent of full capacity, in a cool place. Click the battery status icon in the notification area of the Windows taskbar to check the current charge. Avoid storing a fully discharged—or fully charged—lithium ion battery for extended periods, as this can diminish battery life.