Save Yourself Some Money and Only Replace Your Device Batteries when They Die

For years I had been replacing my device batteries when they started reporting 1 or 0, but was burning through so many batteries considering the 20+ battery-operated devices I have. About 6 months ago I started using Device Activity Check to simply let me know when a device stops responding, and by looking at the most recent battery events I know it's time to swap out the battery.

I have gone through SOOOOO many fewer batteries, with some infrequently-used devices running almost 4 months reporting 0 battery. I even had some in the recycle bin that I popped back in and got another few months of use out of. Obviously, this saves $$ and the hassle of changing batteries so often.

Of course, this may not be ideal for critical devices if they go offline, but for those that aren't as important, I definitely recommend this approach. And if you'll be away for an extended period, you could put in some fresh batteries on the low device(s), and then pop the old ones back in when you return.


I just keep track of all battery changes. After a while you know when you should be replacing them and when you just need to re-pair them.

My experience has been that I can’t expect disposable alkaline and lithium-metal batteries to have a reliable discharge curve like we have all come to expect from the Li-ion batteries in our mobile devices and laptops.

Battery reporting with smart home devices has always been pretty useless for me, whether it was with smartthings or Hubitat.

I agree that using device activity (or lack thereof) notifications is the better option.


In my mind...the single biggest point of reckoning & reconsideration a year after one "dives in" to this stuff.

When you realize that every device placement transitions from:
"oh, that would be cool" to
"oh, crap...another battery",
or as mentioned above with some devices - a "re-pairing or spider web clearing" job.

In concert, the topology can become a maintenance hassle ...and causes one to think twice about "throwing a sensor up" (and where) for modest utility gain.

(My past experience with wireless battery devices was not a big problem with the more expensive, but proprietary, Visonic security system sensors. So that is to say, this doesn't have to be this way and I'd pay more for it not to be. And smaller is not always better when it comes to the reserve power benefits. Clearly smaller AND sipping power is optimal )

There's an opportunity benefit for the HE Community to start awarding Ratings to devices in select Categories of Quality. Reliability, Compatibility, and Strength. Edit: and resulting battery longevity for commensurate utility/use.

I just started using Custom Device Note App to note in the device when I change batteries, filters, etc. But I can almost see using a hybrid of these two apps for this purpose.


That was my first thought: Closet motion sensor versus smoke alarm. Probably 75% of my battery devices fall into the non-critical category, though. I really do need to add one of the notification tools, since we have been in this house for 8+ months. I am due for some upcoming dropoffs.

Like I expect a few respondents and perhaps some that have not responded, I'd add the extra qualification to the title that the device also is one that is actively used...

I have also dove in knee / head deep into Home Automation, including a number of contact and temperature / humidity sensors that may or may not be needed, requiring individually expensive batteries.

My experience is the same, use Device Activity Check to find out when a device stops reporting. That said, I will typically notice that something is not working right prior to that, and after a few years of experience, I tend to know which sensor is mis-behaving, but not always…


That is probably a reasonable approach for the critical devices that you can't let die, but IMO that's a lot of unnecessary work and even with consistent tracking "time-to-death" will probably vary greatly depending on device usage, battery brand, and exact state of battery when received or after being stored before use.

Thanks, I'll check out the Note app and might take this approach. Would be helpful or other uses as well.

It's been a while since some of these conversations have happened (and I would need to do some digging to find them.... ) but the battery life of many devices can depend not only on the setup of the device in question, but the network in between, i.e. the mesh or LAN in between. So a device, as good as it may be at reporting it's status to the mothership, if the comm's in between are not up to scratch then it may as well throw it's battery overboard.....Eventually....

Hence the... environment... can be a factor... and one that does not seem obvious at the time....

If a device is safety critical, I would think you would want to make sure the battery never completely runs down anyway. I'm old school and still change my smoke detector batteries with the fall time change (beside my dog goes nuts when the low battery chirp starts). it's just as easy to change those few safety critical devices out at the same time with the smoke alarms rather than waiting for them to eventually die at the wrong time.

For the non critical ones, yeah may as well let them run them selves out. I have a particular Zooz tilt sensor that is rather amusing. I installed it, within 24 hours went to 2%. after about 10 days was back at 36% for months. a couple weeks ago it was back at 100%, , it bottomed out at zero last week and now its back in that 35% range. That would be a perfect candidate for the Device Activity check app.


We bought the property that is our current home here in Maine in the summer of 2019, intending to visit it periodically with weeks to months between visits. So, around November of that year I installed a number of battery-operated z-wave temperature sensors in spots around two buildings. At the time, I was using a different automation controller. We ended up moving here as Covid hit and ultimately decided to just make that a permanent thing as it beats the heck out of living in the burbs of a big city (but that's another story). Anyway, re battery devices, here's what I've found:

  • Waiting to change out batteriesuntil they fail, if the sensor isn't critical and you live at the property, makes great sense. Otherwise, I'd change them out annually.
  • The longest-lasting, most reliable battery-operated temperature sensor for me has been the little Homeseer brand "triangle" sensor that also reports moisture/leaks. I don't think I've had any of four fail. The only downside is that they use 1/2 AA batteries that I can't find locally, so I order them on Amazon.
  • I have to replace the battery in the one outdoor sensor at least once per year, but it's subjected to a lot of abuse as it sits in the generator housing. I think I've captured temp readings of -4F to 140F with it. If I change the battery out around Thanksgiving it seems to be good for a full year.
  • I have one of these sensors under a kitchen sink and I don't ever recall changing the battery. The temperature there is fairly steady and it has never reported a leak. If so, that's going on 3 years with the same battery. Impressive!