Can you call during a emergency blackout? Introducing the new Uniden Cordless Phone Power Failure Backup Pack giving you peace of mind that your home communication will always be working in a power failure. The BP-100 gives you up to an additional 3 Hours of Talk Time and up to 4.5 Hours of standby time when a power blackout occurs when 3 battery packs are installed in the unit (2 battery packs are included in the pack).