When induced, all smoke detectors in your home alarm concurrently. Tricky-wired detectors are always on and when the power goes out, the battery backup kicks in.???? ??????? ??? ??????? ????? ?? ?????? ?? ????????? ???????? ????? ?????? ??????.??????? ????? ??? ?????: ????????? ????? ????? ?? ?????? ???????Battery-operated detectors are quick to in