So I had one of my First Alert Z-Wave ZCOMBO Smoke & CO Detectors go into the dreaded (though not as bad as fire! ) “low battery chirping mode” this morning.
Exactly one of the situations I was hoping to avoid by using a “smart” device.
According to the “Recently” tab, at 8:15am the battery was reported to be 77% (history shows a drop from 79% to 78% over the last 6 days … seems perfectly normal). In other words: *there was apparently sufficient battery and connectivity to a rather more than sufficient battery capacity at 8:15am& … I’m not sure what time the chirping started though!).
I took out the batteries and re-inserted. The device promptly reported battery level as 1%!
Of course, if the device were a little smarter, then it should offer an additional special “low battery alert” message that corresponds exactly with the start of chirping (or perhaps at a level that is typical of 24 hours before chirping?..), but absent that, I wonder what’s happening here.
This unit uses 2x1.5v AA batteries. Checking with a multimeter, the batteries have about 1v each. I understand that “low voltage conditions” are necessarily considered linear to “battery capacity”, so (1v+1v)/(1.5v+1.5v) = 66% normal voltage does not necessarily correspond to 66% battery capacity.
In other words, I could say the batteries are pretty close to the 77% reported, but I also could understand if the device thinks that 66% is too low and warrants chirping, but how can it report 77% one moment, and 1% after just inserting the batteries the next moment?
I’m going to put the same batteries in a second device and see if it also reports 1%; though I’m not sure that information will help contribute to this problem.
2016-11-30 11:39:22.097 AM PST 19 minutes ago DEVICE battery 1 Den Smoke CO Alarm battery is low! true 2016-11-30 10:48:33.134 AM PST 1 hour ago DEVICE alarmState clear Den Smoke CO Alarm test cleared true 2016-11-30 10:48:33.134 AM PST 1 hour ago DEVICE carbonMonoxide clear Den Smoke CO Alarm carbon monoxide is clear true 2016-11-30 10:48:33.134 AM PST 1 hour ago DEVICE smoke clear Den Smoke CO Alarm test cleared true 2016-11-30 10:48:32.226 AM PST 1 hour ago DEVICE alarmState tested Den Smoke CO Alarm was tested true 2016-11-30 10:48:32.226 AM PST 1 hour ago DEVICE carbonMonoxide tested Den Smoke CO Alarm was tested true 2016-11-30 10:48:32.226 AM PST 1 hour ago DEVICE smoke tested Den Smoke CO Alarm was tested true 2016-11-30 10:48:26.854 AM PST 1 hour ago DEVICE Den Smoke CO Alarm code 13 is 0 true 2016-11-30 8:15:40.710 AM PST 4 hours ago DEVICE battery 77 Den Smoke CO Alarm battery is 77% true 2016-11-30 7:25:17.971 AM PST 5 hours ago DEVICE battery 78 Den Smoke CO Alarm battery is 78% true 2016-11-28 6:55:55.265 AM PST 2 days ago DEVICE battery 78 Den Smoke CO Alarm battery is 78% true 2016-11-26 4:34:11.408 PM PST 4 days ago DEVICE battery 79 Den Smoke CO Alarm battery is 79% true 2016-11-24 4:12:28.679 PM PST 6 days ago DEVICE battery 79 Den Smoke CO Alarm battery is 79% true