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FiOS Internet

Battery Backup Unit (BBU) Indicator Lights

Battery beeping? Fix battery problems with the Verizon Troubleshooter.

You can also Order a replacement battery if necessary.

You have received one of the following BBU models as part of your Verizon FiOS installation. Please look at the photos to determine which model you have.

Models #1 and #2

Figure depicting the model types of the Battery Backup Unit

The models above use a combination of lights and buttons to signify certain conditions, as described below:


Battery Emergency Use - To protect you in an emergency, if an active battery is installed in the BBU, the BBU will shut down approximately one hour before the battery is fully depleted. If you need to make a phone call, press the Battery Emergency Use button once. This will enable the ONT to reboot, and provide you with up to one hour of battery life for emergency calls. After the button is pushed, all remaining battery life is used.

Alarm Silence - Press this button to silence an audible alarm. 

Auxiliary Power:
Not currently available

Replace Battery:
Red - Battery needs to be replaced  
Click here for instructions on battery replacement

Battery Power:
Red - ONT is operating off battery power;
no AC power available

Blinking Red - Battery power is low
System Status:
Green - Indicates normal operation

Blinking Green - Indicates system fault

Model #3
Figure depicting a model type of the Battery Backup Unit  


Green - Operating normally.
Blinking Green - Battery is going through a self-test.
Yellow - ONT is operating from the battery and the battery is discharging.
Blinking Red - Battery is fully discharged and needs to be replaced.

Green - ONT is operating normally. BBU is on standby.
Yellow - Battery is either recharging or conducting a self-test, or the BBU is providing power to the ONT.
Red - Battery is low. When this light comes on, approximately two hours of talk time remain.

Replace Battery:
Red - Battery needs to be replaced.
Click here for instructions on battery replacement

Green - Auxiliary battery pack (ABP) is connected to the BBU, ABP option is currently not available.
Off - No auxiliary battery pack is connected.

See Also: BBU Audible Alarms
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