Well, it doesn't really matter, does it. There is no way to know the actual remaining charge of the RC battery if you cannot trust the indicators. I know that the Phantom would perform a RTH procedure even if the RC in fact went dead, but I am simply not risking it. Also it is impossible to enjoy the flight with that loud beeping going on.
When I connect the RC to the charger, it should keep charging for at least a couple of hours and consecutively turn on all four white LED's. Mine doesn't. The second LED starts blinking but then they all switch off after just five minutes, indicating that the charging has finished. In fact, even if I leave the RC plugged into the charger all night, the app will still only display 20% the next morning. If I then start flying, the acoustic low battery warning is issued after just like fifteen minutes.
I am quite sure that this a hardware issue and needs to be fixed. I expect DJI to do so since my P4 is still under warranty, but it is nevertheless extremely annoying, particularly since this is my second repair attempt for the exact same failure.