When to replace smoke detector batteries
By RemindViaText.
Batteries vs the alarm
Replace backup batteries at least twice a year. Replace the entire alarm about every 10 years — the date of manufacture is on the back. Hardwired units still need the backup battery.
Do it in daylight
The 2am chirp is a failed plan. A scheduled reminder in spring and fall, with “every floor” in the message, is the whole system.