I was woken up this morning at 5am (smoke alarms always have their
problems early in the morning it seems) by one of my smoke alarms
doing three blasts and then going silent a few minutes, then doing three
alarm sounds again, etc. The LED was rapidly flashing green.
Eventually it got worse and sounded continually
so I had to remove the unit from AC and remove the battery.
This model is dual powered (AC with 9V battery backup). The thing
is there was no smoke, no fire or any cause I can see to trigger it.
The other two units were fine (also Kidde model 1275 and a PI 9000 battery
powered) and their LEDS were normal.

Are these AC powered/ battery backed up units unreliable due to
AC power noise, brownouts, etc triggering them? I seem to have
more trouble with the AC + battery ones than I've had with
the battery only units.

Mark