I flashed my LYWSD03MMC with zigbee firmware in December last year, now I replaced my battery, which was at 15% but after replacing the battery percentage remains at 15%. Does this take time, or do I need to do something else? The temperature and humidity works normally after replacing the battery
Edit: After a night’s sleep, the battery sensors are neatly at 100%
so i have OTA updated my sensors to 3001-1100
cant figure out how i can remove the smiley, do i need to send a command to the sensor through z2m ?
HA → Settings → Devices & services → MQTT → Your LYWSD03MMC → Show smiley to “OFF”
or if using Z2M:
HA → Settings → Add-ons → Zigbee2MQTT → Open Web UI → Your LYWSD03MMC → Details → Show smiley to “OFF”
I have had the same problem. I have changed some versions of lywsd03mmc-z.js without luck. Finally I updated zigbee2mqtt and it works perfectly!!
How’s the battery right now after a year of usage? Many batteries had to be replaced?
Some variation, but I put that down to different batteries. Out of the three I ended up converting, one needed the battery replaced after 9 months, the others are still going. So they are doing well enough for me to now be planning to go through the conversion process for the others I have that are running the dreaded newer firmware.
out of my 3 Xiaomi LYWSD03MMC it was possible to flash the firmware on all, but only two would be found as Zigbee device.
The pairing mode was quite difficult to bridge the two pins, so I was working for almost half an hour on the last without sucess.
It did not go into pairing mode.
now will last the rest of its life as a standard temperature sensor, but not integrated into my HA
Same here.
Exact same flow as KRiS.
I’ll continue to research.
UPDATE: I got it working by touching the GND to the Reset and the BATTERY!!
Touch the tweezer to those 2 points and the battery and it worked 
You have a 3-way tweezer??
But seriously, I have the exact same problem. Migrated from zha to z2m. Nearly all devices have repaired successfully. I even found still in box LYWSD03MMC i never setup and that paired successfully.
How are you saying to reset them? You touched all 3 contacts at the same time?
Here it works when short circuiting the RESET and GND contacts for at least 7 seconds. When the display switches to off and on again the reset has completed successfully. Might need a couple of tries because it is a bit tricky to keep a continuous hold on the two contacts.
I made a simple tool out of a 2.5 mm MYW cable to keep the impedance low when executing the short circuit:
Ah yea, that is what I’m doing and I DO get it to reset but z2m won’t pick up the ones that were in zha. Wasn’t sure if there was something on the backend that’s seeing a conflict?
UPDATE: 9-10 attempts later and an HA restart and we’re finally getting some of them connected.
What’s the difference between these two firmwares? I have the latter currently installed from years ago, and it still receiving ota updates via z2m.
I needed to change the battery and afterwards HA did not recognize the sensor anymore. I did a reset and could see it in HA again. After the reset the temperature on the display changed from Celsius to Fahrenheit. HA is still showing in Celsius.
Does anyone know how I can change the temperature unit on the display?
Here changing Celsius to Fahrenheit and vice versa works by short circuiting the RESET and GND contacts for at least 5 seconds.
I did that a couple of times, but will try again. Thank you!
It is indeed a bit tricky. Watch the display while shortening the contacts.
Its nearly IS Impossible to get them into pairing mode and pair to Z2M.
FWIW The devices I migrated over to zigbee generally worked, and battery life turned out to be fairly decent, but I did have issues with them dropping out of the network intermittently (I have a fairly large network, but this was definitely unusual). Sometimes they would come back by themseves, sometimes it needed the battery removed, sometimes they’d need to be reset. All in all I think this has been an interesting experiment, but I have removed these now and replaced with my esphome sensors or standard Xiaomi temp/humidity sensors (the puck style jobs with an image of a thermometer on the outside).
i was having problems with 2 out of 9 after a recent change in my system.
they refused to stay paired (device has lef network).
mqtt2zigbee got update to v2.0 and i migrated from sonoffe e stick (ember) to slzb-06m (ember).
just now i switched back to the sonoff coordinator and everything look fine again.
all i can conclude that zigbee pairing ist influenced by coordinator type and maybe initial pairing. these xiaomis are nice and cheap but should be treated as experimental 
