ORIGINAL: R/C Lightweight

It's likely that your low voltage detection is switched on. This is a safety feature used to prevent Lipo batteries from over-discharging. If your ESC light was solid green before the flashing and half speed started happening, then detection was on, and isn't necessary (or recommended) for Nicad/Nimh batteries. To turn this feature off : Turn on transmitter. Then "tap" and release ESC button to turn it on. Before the ESC gets a chance to start blinking again press and hold ESC button for ten seconds until you hear a sound from your motor indicating low voltage detection is now off. Verify detection is off by checking to see that the ESC light is solid red - no flashing. Hope this solves your issue. The Stampede VXL is a blast.