i think that if the light is operating normally but there is no power being sent to the battery, then it is something internal with the controller, and therefore probably hard to fix. You might wanna open it up and look for anything suspicious (loose, soldered bad, in the wrong place ect)
if you got it off of ebay, i would not reccomend sending the controller back for another one, cuz when i did that 2 months ago, and my car is STILL not here...stupid ebay sellers dawdling.
