Support Battery Backup PowerReserve


The PowerReserve device is used with an Optical Network Terminal (ONT) configured with a Power Adaptor. With 12 fresh D-Cell or “flashlight” batteries, the PowerReserve provides at least 24 hours of backup power for basic voice service, including 911 dialing, in the event of a power outage.

Power Reserve
  • The PowerReserve device is easy to install and can be mounted on the wall, if desired. Please download the PowerReserve installation instructions (pdf format) or follow along below.

      1. Open the PowerReserve door by pressing the latched tab toward the unit and then pushing the tab up.
      2. The PowerReserve device can be laid flat or mounted to a wall.
      3. Uncoil the cable located in the center of the tray.
      4. Insert 12 new D-cell alkaline batteries into the device. DO NOT use rechargeable or Lithium batteries.
      1. Open the PowerReserve door by pressing the latched tab toward the unit and then pushing the tab up.
      1. Plug the power cable into the power adapter.
      1. Close the PowerReserve door.
  • The PowerReserve device will only provide power for voice calls in the event of a power outage. We recommend that use your voice service for emergency calls to preserve your battery power during an extended power outage. Verizon will not provide credits and is not liable for interruptions of service due to commercial power outages. The PowerReserve device will not power cordless phones, medical devices, home alarm/fire systems, your Fios Internet or TV service, or any other peripheral devices.

  • If your PowerReserve device is not functioning properly or has been damaged, you may purchase a replacement at

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  • Using a battery tester (widely available at electronics stores) or the battery test strip included in the box with your PowerReserve device, please remove and test each battery. Replace any batteries that fail the test.

    Replacement D cell alkaline batteries are available from many retail sources. Please store and handle all D cell alkaline batteries in accordance with manufacturers' instructions. When switching out batteries, please make sure to dispose of your old batteries properly. For more information about recycling, you can contact Call2Recycle at 1.877.RECYCLE (1.877.273.2925) or visit to find a list of the drop-off locations closest to you. You may also visit or call the EPA at 202.272.0167 for instructions. Your local municipality may also have information about proper disposal of batteries.

    Please note that lithium batteries and rechargeable batteries are not compatible with the PowerReserve device.