Fully charged 9/10 at 12.45
12.54 at 98%, 9 minutes for 2% that makes 450 minutes, could be as bad as 10. 5 hours
Ok : so it turned out that was going to be optimistically 36 hours.
However, it also transpired that the issue was using the high sensitivity mode to react to the lift motion. Changing back to the default, which some have reported as too slow, is fine in terms of response time but the problem is that rather often it just does not respond at all.
Back on default sensitivity battery life rises to the giddy heights of 3 to 4 days again - still a long way short of the claimed 7 days.
Amazfit do publish how their battery life should be on their support site which is interesting because they only accommodate 15 minutes of running every other day which for a device pitched at fitness seems a little limiting. and their means of testing your own device's battery life is frankly silly.