What is "for some time" ? Some months, some weeks, some days? Mine can survive at least 3 months without recharging.
Was the controller fully charger when you left it "for some time" ?
You indicate it is now fully charged because of the time you left it connected to the charger or you see the progress in the LEDs and it was finally full ?
Maybe as simple as msinger indicates, just how to turn it on?