Broken solder joint on the ESC/Battery wires or perhaps on the connector?
Did you remove the factory connectors and solder on deans?
Other than that I would say you are hosed and would need to send it in to get looked at unless you want to open her up and void any type of warranty.
To run with one battery you have to hook up the battery to the BAT2 input and then short the BAT1 wires
http://www.teamnovak.com/download/in...structions.pdf