eMac: How to Replace the Backup Battery

This document discusses replacing the internal backup battery.

This article has been archived and is no longer updated by Apple.

Your computer has a backup battery that preserves certain settings when the computer is off.

You may need to replace the battery if you have intermittent problems starting up your computer, or if settings such as date and time change when you start up your computer.

You can purchase a replacement 3.6V, 1/2AA leadless lithium battery at most electronics or computer stores.

Click the Next button below for step-by-step instructions on replacing the internal backup battery. You may want to print these pages before you begin, as you must turn off the computer to replace the battery.

If your computer is plugged into a power strip, Apple recommends you leave the strip turned on to avoid shortening battery life.

Step 1: Shut down

Turn your computer off by choosing Shut Down from the Apple menu. Unplug all cables, except the power cord, from your computer.

WARNING: If your internal modem (included on some models) is connected to a telephone line, disconnect the telephone line from the internal modem port before you open the access panel. This prevents electric shock.

Step 2: Position the computer

Place a soft, clean towel or cloth on the desk or surface. Slowly lift up and turn the computer so the screen is facing down on the cloth.





Step 3: Remove the access panel

Use a Phillips screwdriver to remove the screw on the memory access panel. Then gently remove the access panel.





Step 4: Discharge static electricity





Touch metal inside the computer. This helps protect the computer from damage caused by electrostatic discharge.

Always do this before you touch any parts, or install any components, inside the computer. To avoid generating static electricity, do not walk around the room until you have finished installing the battery and closed the computer.

Now disconnect the power cord from the computer.

Step 5: Replace the battery

Remove the internal backup battery and replace it with the new one. Make sure to align the plus sign (+) on the battery with the one inside the computer.





Step 6: Press the reset button

Locate the PMU reset button inside the computer. Push the button for one second using a pen or pencil.





Step 7: Replace the access panel

Hold the access panel against the base of the computer and tighten the screw.





Step 8: Reposition the computer and connect the cables

Gently turn the computer right side up. Then reconnect the cables you disconnected from your computer.

If you need help reconnecting your cables, see the setup documentation that came with your computer, or other topics in Mac Help.

Step 9: Turn the computer on

Press the power button on the side of your computer to turn it on.

WARNING: Never turn on your computer unless all of its internal and external parts are in place. Operating the computer when it is open or missing parts can be dangerous and could damage your computer.

This document contains information from Help Center, the help system included with your computer.

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