Using your battery – Apple MacBook Pro (15-inch) User Manual

Page 77

Chapter 3

Using Your MacBook Pro

Using Your Battery

When the external power adapter is not connected, your computer draws power from

its battery. The length of time that you can run your MacBook Pro varies, depending on

the applications you use and the external devices connected to your MacBook Pro.

Turning off features such as AirPort Extreme or Bluetooth wireless technology can help

conserve battery charge. For more information about using your battery, see

You can determine the charge left in your battery by looking at the battery level

indicator lights on the battery itself. Press the button next to the lights and the lights

glow to show how much charge is left in the battery. The indicator lights remain lit for

a few seconds after you press the button. You can check the charge with the battery in

or out of your MacBook Pro.

If your battery runs low while you are working, attach your power adapter and let the

battery recharge. To replace a low battery with a charged one when you are not

connected to a power adapter, it’s best to shut down your computer. If you put your

MacBook Pro to sleep to replace the battery, wait until the sleep indicator light is

pulsating before removing the battery. Although your computer will shut down when

you remove the battery, you won’t lose any data.

Important:

If only one flashing light is on, very little charge is left. If no lights are

visible, the battery is completely drained and the computer will not start up unless the

power adapter is connected. Plug in the power adapter to let the battery recharge, or

replace the drained battery with a fully charged battery (see page 78).