Battery Backup Unit (BBU) Audible Alarms Your BBU is equipped with an audible alarm to inform you of problems with your BBU. The alarm sounds for two seconds and then is silent for 58 seconds. The conditions listed below are the potential reasons for the audible alarm. You can use the alarm in combination with the indicator lights to troubleshoot your BBU issue.
Low Battery - Alarm is silenced if the battery voltage goes above 12V (electrical power has returned), the battery is fully discharged, or the battery is removed from the BBU.
Foreign Voltage - Alarm is silenced once the foreign voltage has been properly removed.
Replace Battery - Alarm is silenced when the battery is removed.
Overcurrent - Alarm is silenced once the overcurrent has been properly removed.
Since you are responsible for ensuring that a battery is installed and maintained in the BBU, it is very important that you familiarize yourself with the indicator lights and audible alarm to ensure that you have backup power if it's needed.
Please note: During a power outage, only your standard telephone service will receive power if an active battery is installed in the BBU. The BBU will not operate your Internet or video services, or your router. The BBU will shut down approximately one hour before that battery has completely drained. If you need to make an emergency phone call after the BBU has shut down, press the Battery Emergency Use button on the ONT. This should enable the ONT to reboot and provide up to one hour of talk time. After you press the Battery Emergency Use button, the BBU will operate until the battery has completely drained.
See Also: BBU Indicator Lights