As the battery in my Eve Weather thread outdoor sensor went from 100% to 0% in two days, I wonder if it’s related to me using its temperature value in many templates controlling thermostatic radiator valves. Therefor:
Does state_attr(entity, "current_temp") query the HA database or does it actively poll the sensor?
And: Does it make a difference if a sensor is Thread, Zigbee, BLE or something else? E.g. I think my BLE devices only send out the current temperature whenever it changes, but do not listen to anything. Now I wonder if the Eve Weather sensor listens and replies to queries, which would explain why the battery I replaced a few days ago fell to 0% so quickly.
Hmm, I can’t find much about the HA state machine, but maybe that’s too technical for me anyways. My question is: can the frequent usage of state_attr have an effect on the battery state of a thread based temperature sensor? If yes, can I somehow only poll every 10 minutes and cache the value in HA?
Thanks, so the frequency of accessing a sensor in HA has no effect on the battery usage of the device. Then the battery seems to be dying for another reason.
Yes, that is correct. Look at the device configuration to see how often or the rules as to when the temperature data is sent. For a battery powered device this should be no more than every 15 minutes, ideally an hour. Alternatively if it’s has a threshold reporting configure it for reporting every 1-2 degrees. If you need faster you’ll want a line powered device (or replace the batteries every day)
Thanks. I can’t find any information about the update frequency & threshold for the Eve Weather, but based on the temperature graph its about 5 minutes. The first CR2450 battery was okay for an entire year. Only last week I replaced batteries and moved it from Apple Home to Home Assistant. Yesterday I added templates to automate heating, and now it fell from 100% to 0% within a day. Must have been a coincidence and a bad battery.
Or it is communicating using a fundamentally different path. I’d look at troubleshooting that. See if others had issues with that sensor after connecting it to HA.
Thanks. In the past days I’ve seen a couple of reports regarding Eve devices sending false battery percentages – sometimes they stay at 100% for more than a year, sometimes they drop rapidly to 10% but are back at 100% when removing the battery for s few seconds, sometimes they show 100% but the battery is already so dead that only the display remains on, but all transmissions are off. So it was a false alarm, I will not trust these percentages anymore.