The battery backup for vehicle emergency communicator includes mechanisms for applying backup battery power to an emergency communicator. Electrically operated relays may be employed to switch the backup battery in order to power the emergency communicator of a telematics device. When relays are used in the system, failure of the car battery causes normally open relay contacts to close, applying backup battery power to the emergency communications device. Normally closed relay contacts open to remove connection of the failed battery to the emergency communications device. Additional features of the battery backup for vehicle emergency communicator may include a battery charger, an uninterruptible power system (UPS), transistor switches, an emergency contact dialer, and a timer that limits application time of the backup battery.