I've seen this happening with a Phantom 3 standard before. For me, it wasn't the battery or the cable, but the actual USB connector on the controller. It seemed like they didn't do a great job in the factory soldering the USB connector to the printed circuit board that it sits on. Once you've ruled out that your issue isn't a bad USB cable/charger, you may want to consider this. If you look at this picture, you'll see that the USB port is attached to a little circuit board that is wired to the rest of the controller. I was able to repair the connection between the USB connector and that board with a fine-tip soldering iron, if you're handy with a soldering iron you may want to try the same. If you aren't experienced with a soldeirng iron, I was able to find a replacement part on eBay (but nowhere else so order soon!).