o For many years, your home telephone service would allow you to stay connected to emergency voice services during a power outage. However, if your residential voice service is now provided using fiber optics rather than the traditional copper-based line, it requires backup battery power to continue functioning during an outage. To avoid a disruption of home voice service during an outage – and to maintain the ability to connect to 911 emergency services –YK provides a battery for the backup power for your residential voice service during the initial installation at no additional cost. Backup batteries are expected to last at least eight hours on standby power and should give you at least six hours of talk time.