@Alanm on my old Mini 1, I posted some steps on here (which I can’t seem to find now) on how to update the battery firmware.
I had to do the same thing for the Mini 2 this week.
Essentially it was:
- Update the drone firmware, which also does battery # 1
- Shut down RC, Drone and force-quit the Fly app
– This was the important part!
– Don’t just close the app to the home screen, force kill it completely - Put battery 2 in, power everything up
- Check for latest updates and you’ll be told new firmware is avaialble
- Wait while it updates the battery
– This is very quick, as it’s only doing the battery and not the drone and rc again - Shut down everything, force quit the app
- Put battery 3 in, etc