Weird Smoke Detector Problem

[Matt Mason]

This is what I got:

FIREX brand detectors. 120 VAC hardwired with battery backup.

Detectors are relayed to each other (total of 6), so if one goes off, they all go off.

One detector started giving the signal its battery backup was low. Replaced the battery, it still beeping and diode light indicated battery was low.

Replaced battery again. Still low battery.

Replaced detector with a spare. It indicated low battery

Pulled one detector (that was fine) from another room and installed it. It began to indicate a low battery.

I checked the wiring, its good. The smoke indicated it is receiving power.

If I test the detector, it sounds and will set off the other detectors as well.

What the hell is causing the low battery warning then? Not enough voltage from the 120 VAC source? Bad neutral? Evil spirits?

thanks in advance...

Matt

[Don Phillipson]

How old are these units? The americium sensor does not last for ever. I had to replace the HW units in my house after about 7 years (with battery-only since there were then frequent electricity supply outages.)

-- Don Phillipson Carlsbad Springs (Ottawa, Canada)

[Matt Mason]