Battery level estimation

Battery level indication is difficult to estimate accurately. 

Our current battery level estimation algorithm isn't perfect, but we are set to improve it. In our battery level estimation we strongly rely on battery voltage output measurements. The accuracy of battery level estimates are higher when the battery is charged fully, prior to your flight and when used in one flight, not multiple

The accuracy of battery level indication decreases  with multiple flights with the same battery (in one session), because battery load affects voltage. Battery voltage at rest and while loaded will give two completely different readings. That is why you can see a fast battery level decrease in the beginning of your flight quite rapidly and it increases after you land AirDog.