There’s nothing you can do to ‘boost’ the power without modding, any device connected is limited to how much current it may draw (not a lot) but a gamepad should be fine.
The extension cable is obviously the problem, not all usb cables are equal and cheap cables are especially hit and miss. Also the length of the cable may drop the voltage enough to cause issues. Strange that it worked the first time though. The only other thing I can suggest is try another cable or use a powered usb hub.