I have 3 Nest protects. All three give the bright green "nightly promise" when I switch out the lights, suggesting they're working fine. All three are showing in the Nest app as "everything OK". However, for the remainder of the night two of them have a brief, green light flicker every 60 seconds; the third one, has no such flicker.
The two which have the flickering light are marked as model A0124 on the back. The one which does not have a flickering light is a bit older, and is marked as model A13 on the back. However, all three are 2nd gen, all are battery operated, all have the latest firmware, and all are connected to the same wifi.
Why is the behaviour different?
Typical old-fashioned smoke alarms invariably have a red light which flickers every minute or so to confirm the battery is working and everything is OK. My understanding is that Nest replaced that flicker with the Nightly Promise feature instead. I really, really liked that design - the Nest Protect clearly tells you it's working once before you go to bed, then it has no more lights for the rest of the night. The perpetually flickering red light of old-fashioned smoke alarms drives me insane when I'm trying to sleep. The idea of using Nightly Promise as a replacement was genius.
My older Nest Protect (A13) is awesome. The newer Nest Protects are irritating me immensely with this every-60-seconds light flicker, which is exactly like I'd expect to see in an old-fashioned smoke alarm (albeit it's green instead of red, but whatever). Why do we need this crap if the Nightly Promise has already confirmed everything is good?
Really want to hurl my two new Nest Protects out of my window and into the harbour.
Yes that's what I did in the end @lulukas . It still annoys me though. I spent hours on the phone to Google's product support, but they have not been told by their product development team that anything has changed so they just assumed I was an idiot and nothing had changed. They actually asked me if the blinking I was referring to could be the path light - I mean seriously? Anyway the only way to get them to even acknowledge there is something there which they're missing is if I take all 3 devices down, sit them next to each other, video it, and send them the video. Maybe I'll get around to doing that one day, but so far I have not found the time.