Bluetooth LE loses connection after 24h


I use a bluetooth LE connection for a device called Freestyle Libre, a blood glocose sensor. I noticed that my Fairphone 4 loses the connection after around 24h. After that I have to actively wake up the connection (in this case: using a NFC scan) and everything is working for the next 24h.

I addition to that I use a Xiaomi Mi Band 4 via BT (I assue LE too), but that connection is totally stable.

Since this is a important medical device for me and I did not encounter those issues with other phones I was curious if this is a configuration issue on the fairphone?

I dump a part of my adb shell dumpsys bluetooth_manager in the working state:

Bluetooth Status
  enabled: true
  state: ON
  address: XX:XX:XX:XX:XX:XX
  name: MY Fairphone 4
  time since enabled: 41:12:22.516

Enable log:
  01-12 16:00:03  Enabled  due to SYSTEM_BOOT by android

0 BLE apps registered


  Name:  MY Fairphone 4
  Address: XX:XX:XX:XX:XX:XX
  BluetoothClass: null
  State: ON
  MaxConnectedAudioDevices: 5
  A2dpOffloadEnabled: true
  Discovering: false
  DiscoveryEndMs: 0
  Bonded devices:
mSnoopLogSettingAtEnable = empty
mDefaultSnoopLogSettingAtEnable = null


GATT Client Map
  Entries: 2

  com.freestylelibre.app.de (Registered)
  LE scans (started/stopped)         : 0 / 0
  Scan time in ms (min/max/avg/total): 0 / 0 / 0 / 0
  Total number of results            : 0
  Application ID                     : 6
  UUID                               : a18e9665-090b-44c5-99f8-b5d3d32c42c5
  Connections: 1
    01-14 02:26:43 - 24326927ms : 18:32:19:0A:02:DA (6)

  com.eveningoutpost.dexdrip (Registered)
  LE scans (started/stopped)         : 0 / 0
  Scan time in ms (min/max/avg/total): 0 / 0 / 0 / 0
  Total number of results            : 0
  Application ID                     : 9
  UUID                               : f67402b9-a42c-4b92-b280-fa5ff5996b2c
  Connections: 1
    01-12 16:01:07 - 148262007ms : ED:54:44:B5:9C:A3 (265)

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Go to settings, search for “battery optimisation”, click on “battery optimisation”, change the filter to “all apps”, search for “Bluetooth”, change to “Don’t optimise” and see if this fixes your problem. If not, you should contact support.


Thank you, I will try it.

I just had my daily 24h disconnect without the Bluetooth app battery optimization. But I will observe the behavior for a few more days (and after a reboot) before contacting the support, just to be sure.

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Did you disable battery optimisations for the FreeStyle Libre app as well?
Maybe that’s the one that’s actually getting killed :thinking:


Sure, I did this in advance, because I knew this could be an issue from other phones. I was not aware that I could try this on the bluetooth app itself.

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Sadly the problem still remains, even after disabling the battery optimization for bluetooth and affected apps. :frowning: Thank you for your ideas so far. I gonna contact the official support now.