I allow myself to update here with a new question that I also posted on the thread
https://gbatemp.net/threads/wii-u-gamepad-battery-blinking-but-still-on.620199/post-9965320[/URL] :
Wouldn't there be a way to either switch off the red LED of the Wii U GamePad, or, even better, to make the Gamepad think that it still has battery in (that is true), so I can turn it on even when the Gamepad is supposed to be blinking red ? (I've got a 3600 mAh battery that has more autonomy, but it blinks red and stays like this way longer than it should)