Apple MacBook Pro (Late 2007, 2.4/2.2 GHz) - Manual (Page 29)

Chapter 2 Life with Your MacBook Pro 29
Using the MacBook Pro Battery
When the MagSafe power adapter is not connected, your MacBook Pro 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 the battery charge.
If the 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 using
a power adapter, shut down your computer and follow the steps on page 37.
You can determine the charge left in the battery by looking at the battery level
indicator lights on the battery itself. Press the button next to the lights and the lights
will glow briefly to show how much charge is left in the battery. You can check the
charge with the battery in or out of your MacBook Pro.
Important: If only one indicator light is on, very little charge is left. If no lights are on,
the battery is completely drained and the MacBook Pro won’t 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 44).