Mamba Max internal BEC limit?

Ok... somthing whack going on here...... I connect the lipo battery and I'm met with fairly large sized sparks from the connecter and the ESC wires heat up rather quickly :(

This thing worked fine on 3s last week so the ESC shouldn't be toast.........

Edit... I'm a F$%^ING idiot! polarity is backwards... god dammit! :p


Which battery should I connect first, ESC @ 14.8v or the reciever?