No Dial Tone on Your FiOS Digital Voice Phone
If you have no dial tone on your phone connected to FiOS® Digital Voice service:
*Important Note The Battery Back-Up Unit is designed to use a 12-Volt 7.2 Ah SLA (Sealed Lead Acid) battery. Use of a different battery type is not recommended since other battery types may impact the performance of your FiOS services. Verizon is not responsible for damages which result from use of an improper battery. Batteries may be obtained at verizon.com/fiosaccessories or at a third party retail vendor. If troubles persist, contact Verizon Technical Support.
See also: FiOS Digital Voice Service