12v?! Are you thinking of entering any races?
By the way, just so you know, the bar next to the capacitors is B+, the middle one is M-, and B- is um... I forgot... Oh ya the only remaining bar (the one furthest from the capacitor bank!)
Also, the 12v power to the control section shouldn't share the same ground as the traction battery pack (or in your case, the OTHER 12v battery. hehe)