Everyday Computer Skills · Keeping It Running · Lesson 3 of 5

Laptop Battery Health

Why laptop batteries wear out and how to help yours last longer.

How laptop batteries age

A laptop runs on a rechargeable battery, a battery you can fill up again by plugging in. Phones work the same way.

Every rechargeable battery wears out slowly. This is normal. A new laptop might last a full day on one charge. A few years later, the same laptop may only last a few hours. Nothing is broken. The battery simply holds less than it used to.

Batteries age by charge cycles. One charge cycle means using up a full battery's worth of power. It doesn't have to happen all at once. If you use half the battery today, charge it, then use half again tomorrow, that adds up to one cycle.

Many laptop batteries are built to last hundreds of cycles before they hold a lot less. So charging often is fine. You don't need to wait for it to run all the way down.

Heat is a battery's worst enemy. Heat makes a battery wear out faster. Some easy habits help:

• Don't leave the laptop in a hot car or in strong sun.
• Use it on a hard, flat surface, like a table.
• Avoid blankets, pillows or a bed. They block the air vents.
• If it feels very hot, close some apps and let it cool.

Cold isn't great either, but heat does the most harm over time.

Battery settings and power modes

Your computer has settings that show how the battery is doing and help it last longer each day.

On Windows, open Settings, then System, then Power & battery. Here you can:

• See which apps use the most battery.
• Choose a power mode.
• Turn on Energy saver, which cuts back on background work when the battery runs low. Some versions call it Battery saver.

A power mode is a setting that trades speed for battery life. Windows offers three:

• Best power efficiency makes the battery last longest.
• Balanced is a good middle choice for most people.
• Best performance is fastest but uses more power.

On a Mac laptop, open the Apple menu, then System Settings, then Battery. Next to Battery Health, click the small info button. You'll see a condition:

• Normal means the battery is working as expected.
• Service Recommended means it holds much less charge than when new, or something is wrong. You can keep using it, but plan to have it checked.

Some Macs also show Maximum Capacity, how much the battery holds now compared with when it was new. Mac laptops also offer Low Power Mode to stretch the battery.

A worn battery can often be replaced by a repair shop for much less than a new laptop.