‎How long do 123 batteries last in a smoke detector? | SimpliSafe Support Home
gesmemike's profile

Wednesday, June 12th, 2024 8:53 PM

How long do 123 batteries last in a smoke detector?

We've had several issues of false alarms, and each time this seems to be solved by replacing with fresh batteries. But it seems we have to do this every 4-6 months. This week, we had an alarm start chirping due to low battery, but again, it was only about 5 months old.

I know the website says 3-5 years, but is it really that in practice? I've been using Energizer brand. Any brand recommendations?

We have 9 detectors and this is becoming a large expense :P



5.9K Messages

1 month ago

@gesmemike I have eight smoke sensors and they all work fine, with batteries going the distance of 3-4 years and then I proactively replaced them. What I didn't do when I first got my SS2 smoke sensors years ago was to read the owners manual. Two false alarms later my wife politely but firmly suggested I read the manual.  I clean them all once a month and, 11+ years later and with my SS3 since the fall of 2017 (I was a beta tester) not one false alarm.  I buy a case of compressed air cans at Costco about every two years, grab a step stool and gt through them in under 20 minutes.

Location is another factor. I suggest you call support and investigate what is going on.  BTW, one is the new combo smoke/CO sensor.

Please post your outcome here after you call support.


Community Admin


3.1K Messages

1 month ago

Hi @gesmemike, 

The Smoke Detector does have an expected battery life of 3-5 years. That does depend on usage, but even then its battery should certainly last longer than 6 months. Do you notice this battery drain with all of your Smoke Detectors? Or is it just one that exhibits this behavior? 

We do recommend the Panasonic CR-123A Lithium 3V for the Smoke Detector, so testing that brand of batteries could be a good first step. But when your Smoke Detector(s) chirp, do you see a steady yellow light, or a flashing yellow light? A flashing yellow light indicates a low battery in the device, but a steady yellow light means that the device is not fully attached to its bracket. 

If the light is a steady yellow, I would recommend dismounting the Smoke Detector and then put it back on its mounting bracket, twisting it all the way until you hear it click into place. If it clicks into place and the steady yellow light is still there, that could mean that the mounting bracket is screwed into your wall or ceiling too tightly, causing the plastic to warp slightly. In that case, it can help to unmount the unit and slightly loosen the screws - then try mounting the detector again.

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