First Alert Smoke & CO: Battery level report very wrong...?! CHIRP! CHIRP!

Wouldn’t that be nice? Can’t really say what’s going on in their firmware though.

I ran into this problem just today, as the first of my units started chirping at 77% battery. I wouldn’t hold my breath for a firmware fix for these, so I figured I’d just re-calibrate their existing battery report to the approximate 77-100 range that it seems like these actually work in. I grabbed DH code off Github from the link above and changed line 190 to this:

map.value = (int) ((cmd.batteryLevel - 77) * 4.347826087)

That definitely won’t help with accuracy or the frequency of reports, but at least the values it reports would make more sense since they’ll be scaled appropriately.

3 Likes

How often do these First Alert combo units report battery level, and is there any way to force it? Yesterday I tested one of my units and it immediately went from reading 88% to 1% and started chirping. I replaced the batteries, and tested it, but it still hasn’t reported the new battery level.

If you read the posts above, you’ll see that the “1%“ is what smartthings uses when it receives a special “low battery!“ Message from the device, but the device might send that message at anywhere the manufacturer thought was significant, even 70%.

All smoke detectors, regardless of brand, try to use as little battery as possible to stay ready for a real emergency. And since even sending a battery report uses up battery life, they tend to report much less frequently than many other device classes.

I don’t know specifically for this model, but most of the battery powered smoke alarms I’ve looked at only report the battery level once a week. And they do send a “low battery!“ message much sooner than most other devices as well, typically quite a bit above 50% reserve.

So… The dropping from 77% to 1% probably is an artifact of the way smartthings handles the “low battery!” Message. It might well just have dropped from 77% to 70%, for example.

And the reporting frequency may well be just once a week, that is typical for smoke detectors. You could contact the manufacturer to be sure.

Both of mine are above 80%, however I have moved them on Edge driver, and there is no battery capability in history. I have them on this batteries for more than a year.


Added this just to see if it’s monitored by SmartThings

1 Like