Dell notebook computers use two sets of lighted indicators to signal battery life and health, one on the computer itself and the other integrated into the battery. Between the two of them, they can indicate charge level, signal charge-cycle progress, warn you about a defective battery or alert you to one that nears the end of its operating life. Some of these indicators light up on their own; others show up only in response to your actions.

Low-Battery Warnings

The battery status light signals how much life remains in the current charge of your Dell notebook battery. Depending on the computer model, this light may be located on the left edge of the system or on the top near one of its hinges. When the light blinks amber, your charge has dropped low enough to provide only about 15 minutes of operating time. When the light stops blinking and turns to solid amber, you have only about five minutes left before the charge runs out. Unless you press a key or touch the trackpad, or the system responds to some other input/output need such as a pending download, your computer goes into suspend-to-disk mode after one of these low-battery signals.

Remaining Battery Charge

When you close the lid and turn your Dell notebook computer face down, you can access the battery and use its self-test capabilities to monitor how much life remains on its current charge. Press and release the status button on the battery itself to see how much operating time it can support without recharging it. Each of the battery's five indicator lights represents 20 percent of a full charge. If all five indicators light up, your battery is between 81 and 100 percent charged. A fully discharged battery can't trigger any indicator lights.

Remaining Battery Health

The same status button and indicator lights that signal a Dell notebook battery's charge level also can give you information about battery health. Instead of pressing the test button and releasing it, press and hold it for at least three seconds to see a battery health report. Instead of representing remaining battery life, the indicator lights show how much the battery has degraded. When you test a healthy battery, no lights appear. If you see five lights, replace the battery.

Other Battery Warnings

If you try to charge a Dell notebook battery while it remains too hot to accept a proper charge cycle, the battery status light blinks green and amber. This same blink pattern also appears if you accidentally install the wrong type of battery in your Dell system -- nickel-metal hydride instead of lithium ion, for example. Rapid orange flashes can signal a defective battery. While the battery charges, the status light remains solid green, switching to a blinking green light when the charge nears completion.