Battery Checker Rule Showing Wrong Device

I have a pretty simple rule:

The device with the low battery is the Driveway Camera. However, the notification shows the Master Bathroom Leak Sensor (which is 71%) as the notification text for %device%... what am I doing wrong?

That's because you combined all your devices into one trigger. Any of them changing but one of them being below your threshold will match that trigger, even if the device that changed is above your specified value.

The solution is to break each device out into a separate trigger:

Sensor 1 battery becomes < 10 OR
Sensor 2 battery becomes < 10 OR ...

Then the trigger will be matched only when a specific device reports a value below 10. This is the difference between what matches a single, combined "any" trigger vs. separate triggers for each device, even though these triggers look similar.


So the “becomes” isn’t really following the definition of that word? “Becomes < 10” sounds like it shouldnt trigger unless it was above 10 before. Is that not how it works?

The description of the trigger is Rule Machine's best-guess approximation of an English description. But there are two things to note:

  • as above, a single "any" trigger will match if any device changes and any report a value under 10, even if not the one that changed

  • a single trigger like "Sensor 1 battery becomes < 10" will match both when the battery changes from 10 to 9 and from 9 to 8. Rule Machine does not compare it to previous states, so "becomes < 10" really means "becomes any value such that the new value is < 10".

My suggestion is to ignore the English and just look at the mathematical symbols. They won't mislead as much. :slight_smile:

PS - I recommend looking at your devices and seeing what kind of battery levels they report. I think a lot of mine would die beforehand they report 10%. I also find battery monitoring unreliable in general. I use Device Watchdog to monitor device activity instead. Your preferences may vary.

Actually, there is a much easier English definition of the trigger.... IS < 10. The trigger should not be BECOMES because it is not a threshold. It should be IS less than. It's really a lot simpler than you (and Bruce) are trying to make it. But he doesn't see the value in changing it.

I don't recall trying to make it complicated. :wink: I was just reporting what the current behavior is. Again, I suggest ignoring the English and looking at the symbols (plus "is" or "becomes," which does make sense when there isn't anything else involved, e.g., "motion becomes inactive").

Yes, absolutely. But we aren't talking about motion. We're talking about a numeric value. Aren't we? The trigger is not the English meaning of the word becomes for numeric values. It does apply for binary states like motion. If motion is active, the sensor has to BECOME inactive for the trigger to occur. That is perfect. But if the old value is 9 and the new value is 8, the value has NOT, by the English definition of the word, become < 10. It was previously less than 10. Can we agree on that much?

I'm interested in helping the original poster, not arguing with you about something that doesn't matter once you learn how the tool works. I have already said this, which is the only definition under which I think the wording makes sense:

A bit of a stretch, but it works. :slight_smile: (I also addressed the specificity of my motion example above, so calling that out again is not needed.) I'm guessing it's easier for them to just code "becomes" into everything--and again, it's of little consequence once you learn how it works (though my preference would probably be to use only symbols and maybe "is" to avoid any of this...). This is all I will say to not derail this subject; feel free to start your own thread in the Debate Chamber if so desired.

EDIT: At no point did I say anyone was "wrong." I was pointing out how to make sense of the reality that we are working with, and I have no desire to constantly label anyone "wrong" or "right." :man_shrugging:


I had gone through making rules etc for telling me if my batteries were low and found Device Watchdog a great app in place of making my own rules. You choose which batteries you want to check on and what percent down you want to be notified on. Also tells you when each device checked in so you know whether a device/battery are functioning. Check it out [RELEASE] Device Watchdog.
It even works in dashboard with its own tile to inform you if a battery is below the level you set. Can't say enough about this app. Bryan, the developer is FANTASTIC and very receptive to questions or issues.


HSM has custom rule for battery level monitor as well but you are absolutely right about device watchdog. It's a beast and more.

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I didn't think you were making it any clearer for the OP because I understand how it works and I could barely follow you. I thought there was an easier way to put it. And I said so. You're the one who started the debate saying I was wrong. Not me.

Thanks all, I get what it's doing. It's just the wording doesn't match up with what it actually does. I'll try Device Watchdog

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Nope, it sure doesn't. Glad you got it working.