And now I know the battery life: a shade over a year on one CR123 (410 days to be precise).
Changing the battery is easy enough: undo the little hex set screw at the back of the handle, slide the handle cover out, change the battery, the handle reboots and calibrates itself I guess (it makes odd motor noises), and you’re done:
This is much less battery life than my BeCode AIR+ that gets about the same usage, has been running for 1 year and 9 months on a smaller single coin cell, yet shows no signs of quitting. I’m guessing the useless BLE transmitter inside the handle accounts for the wasted power.