Hi!
I have a Mavic Air Fly More combo with 3 batteries and one of the batteries has only 3 LEDs working.
If  I charge the battery fully and press the battery button only 3 LEDs  light up, same when starting an aircraft or whatever else situation  where all 4 LEDs should light up, only 3 do. If I check from the DJI Go  app it says battery 100% and no problems have occured during flights so  far.
Should I be worried, as there is apparently something not right inside battery?
The other 2 work as they are supposed and all 4 LEDs are working on them as they should.

Faulty LED by the sound of it, open a case, batteries only have 6 month warranty.

Could you please provide me with a screenshot of the battery info on the app and the picture of the battery LEDs as well as the serial number? For your case, I suggest sending the battery in, we will help to take care of it. Please contact our support to start case: http://www.dji.com/support

Hi Thor!
Here are the images.

I opened the case and the battery is on the way in.