Hi,
it's a very nice idea which I had some days ago too.
Regarding the linked blog article, every LED has its own rechargeable battery. I think he used a 3d printer to get the holders for the LED.
It is not so much work to do.
At first you need the holders. Then you need the LEDs and a little tiny battery, soder a battery connector to the LEDs et voila, you have the flight lights.
My problem is, I have no 3d printer and to get the holders with the right meassurement is not easy
BR
Edit:
A better and perhaps easier idea is to connect the LEDs to the
Tello battery.The batteries does not take much power, so there might not be any drop of flight time.
Does anyone know the battery connector to soder the cables?