Xiaomi Sensors - Battery Level - anybody know what it really means?

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Hi all. I have a bunch of Xiaomi sensors - temperature/humidity, door/window, motion. They all report a battery_level - but I’m not too sure exactly what the reported number actually represents. Looks like this:

xiaomi battery
xiaomi battery799×398 44.6 KB

Is it %? I know that even when these devices are brand new, I don’t think I’ve ever seen anything > 55 or so…

Thanks,

Tom

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It must be %, the plug sockets show 100

All my sensors arrived at around 47. they have only changed by 1 - 4 in 6 months, cant see battery levels in the app to compare but doesn’t seem right

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That makes the most sense to me also … but like you, I have never seen a sensor > 50 or so. Seems like if it was really a percent, some of these things would have been near 100% straight out of the box brand new.

The good news here is that I have never had to change a battery yet in the 6 months I’ve had them …

Thanks,

Tom

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Why not try to swap a battery anyway, just to see if the indicated battery capacity changes? I’ll give it a try if I remember to buy the right type of batteries the next time I’m at my local tech/gadget store.

My sensors all report somewhere between 31-49 (%), newer ones slightly higher than older ones.

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Ok - so quick experiment. I replaced the battery in one of my motion sensors. These sensors use a 3V CR2450 Lithium battery. With the battery that has been in the sensor for several months, the battery_level was being reported from HASS as 45. When I took the battery out, I measured the voltage at 2.98. The new battery had a voltage of 3.25V fresh out of the package. When I replaced the battery, HASS still reported the battery_level as 45.

So…still no idea what the heck battery_level means :open_mouth:

Tom

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No, me neither. I bought a 3V CR1632 the other day to try with one of my door sensors and fitted it this morning. Battery level changed from 49 to 55, not quite what I would have expected but at least it changed.

Edit: within minutes, the battery level dropped to 51.

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I’ve graphed the battery level value.

image
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As you can see, once it reaches a value is almost flat. Maybe a signal level?

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Fascinating graph, revin.

I’ve read everything on every forum about Xiaomi Aqara sensors, and it seems that the battery_level reported is simply meaningless?

So what happens when the sensors run out of battery, they just silently stop working?

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@revin,
Would you mind sharing the code snippet for your graph?
Would love to use that!

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I’ve had a motion sensor not working properly for a while. The current battery level is being reported as 33, so that is possibly the minimum level to operate correctly. Haven’t put a new battery in it yet.

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I posted some background here: Xiaomi Aqara > Battery level

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I am having serious problems with the Xiaomi temperature sensors. I have tried changing batteries, as you can see in the attached timeline. But batteries drains very quickly (within one or two weeks), I loose connection to the sensors. I wouldn’t mind if the battery reading was wrong, as most of you points out, but I do experience drop-outs when the battery gets to about 60%. Then I can push to button on the sensor to get it working again, and it runs for about 1 week more to about 35-37% and then it drops out again.I have tried changing batteries, but with same results.

batteries
batteries1309×149 18 KB

Am I doing something wrong, how can you get your sensors to work for months ? - When I only get weeks ?

Hoping for some advice on the matter, as I now have 6 sensors that all have the exact same behavior.

/snowatom

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Are they far away from the gateway? It could be due to low connectivity.

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Well I have 6 sensors around the house, and the gateway somewhere in the middle. But all acts the same no matter the placement.

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I had this connectivity issue. For me It was 2.4ghz wifi interference as the frequencies are close to Zigbee. Try manually setting your wifi router to a channel away from 11 like 1 or 5.

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Same behavior here.

Did you find any solution?

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Try @Haden suggestion as this is most likely not a battery issue.

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After the sensors was lost a couple of times, it stabilized. It would seem that a voltage of some sort in the batteries causes this. I am using different brands of batteries, all with same issues. But when the Battery level gets below 40%, it seems to hold its voltage and the sensors are not loosing connection any more.

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Can someone please paste a snippet of the code to read the batteries? Still does not work here after 2 hours for the Switch and Cube… as they only have it as attributes.
I read the same attributes from the hue motion sensor, but it just does not work with the xiaomis.

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Here you go. 

  - platform: template
    sensors:
      bedroom_thermometer_battery:
        friendly_name: "Bedroom Battery"
        unit_of_measurement: '%'
        value_template: "{{ state_attr('sensor.temperature_158d000234878e', 'battery_level') | round(0) }}"
        device_class: "battery"
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