Yeah, that makes sense, thanks. Out of interest, how many charge cycles/years would you expect to get out of a battery? I've had to replace them a few times now and they're not cheap!
Batteries deteriorate over time and yours must be several years old by now.
The % indication can be misleading but the cell voltage isn't.
Both of your batteries already have very low cell voltages before you launched, much lower than the %...
If you Design aircraft for a living, Then why on earth would you hover a drone to get an idea of how long the battery will last!? I don't have to explain to you why that wont work!...Do I?