If you used two different controllers and one was a 2.4G radio and it ran away it HAS to be in your batteries. They might be tight in the battery box but the connection in the box (soldered wires) itself might be bad. You NEED to tape them to be safe anyways. I was going to say it was your reciever and the antenna maybe came loose from the solder inside teh reciever but it did it on your 2.4G. Has to be your battery box.