Support Battery Backup

Battery Backup Information

Solve battery backup related issues with just a few clicks

If your home phone service is provided through our state-of-the-art fiber optic network it requires electric power to operate. Depending on your Verizon equipment, you have one of two backup battery options available for your Verizon voice service - either the PowerReserve or the Battery Backup Unit. With a fully charged battery in place, you will have up to 24 hours of backup battery power for emergency voice services, including Emergency 911 dialing, dependng upon your specific device.

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power reserve


battery backup unit

Battery Backup Units


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  • An alarm will sound once a minute to alert you if the 12 volt battery in the battery backup unit (BBU) it is not fully charged or has been drained completely. Your battery unit may look different from the one in the illustration below. The steps to mute battery beeping are the same for all battery backup units (BBU).

    To stop the beeping

    Locate your battery backup unit (BBU)

    • Press and hold the Alarm silence button for 10 seconds
    • You should either hear a loud beep or the lights will flash on and off
    • If you did not get a beep or flashing lights, press and hold the Alarm silence button and the emergency use button together for 10 seconds.

      Note: This will reboot your BBU and clear the alarm.
    BBU alarm silece buttons

    Note: The reboot will temporarily disrupt all your fios services and take between 3 to 5 minutes to complete.

  • Disconnecting and replacing the 12 volt battery in your BBU

    The steps to replace battery are the same for all battery backup units. Your battery unit may look different from the one in the illustation below. If you are having trouble accessing your battery, click here for detailed information on accessing your battery.

    Important: Before you begin, unplug the BBU power from your wall outlet.

    • Then open the battery compartment.
    • Remove the plug connector with the red and black cables by pinching and sliding it out of its location.
    • Gently disengage the retaining clips that hold the battery in place and remove the battery.
    • Disconnect the battery clips from the old battery and set the battery aside for proper disposal. If you are not installing a new battery, proceed to Step 8.
      Save the red and black cable for future use.
    • Remove the plastic covers on the black and red terminals of your new battery. Connect the battery clips to the corresponding black (- negative) and red (+ positive) terminals on the new battery.
    • Slide the new battery into the battery compartment , securing it underneath the retaining clips.
    • Insert the plug connector back into position. If the battery is installed correctly, you'll hear a beep and the battery power and system status lights will be solid green.
    • Replace the battery cover and plug the BBU back into your wall outlet.

    Changing your battery backup

    To better assist you with disconnecting and installing new batteries in your BBU, we've created a simple two minute video that can walk you through each step. Click on the video to the right to start watching.