i dont understand how all smoke detectors can go out at once.
My only experience is when they are all hardwired together and I get that annoying chirp when battery starts to go dead in one of them
I replaced mine at the 10 year mark.
btw, the house is on fire and the ring doorbell is still going and can pick up sound on the side of the house when the guy is yelling at the people. sound quality pretty good