I've written a basic Python script [1] to read the battery voltage from this device. More details here [2].

Could easily integrate with Home Assistant. Might give it a go actually.

It reads the real time voltages, not voltages stored in the embedded device's memory (for when there is no BLE connectivity while it's running). If there is interest, I can work out this part too.

[1] https://gist.github.com/x1sec/3af7efdcd3465aac09093081c32ba3...

[2] https://doubleagent.net/hardware/ble/bluetooth/2023/05/23/a-...