Just received my new Traxxas TQi 6507 (with Docking Base)

I've fitted a Hump Pack Battery to it. Tried plugging in a TX Charger and no joy.

Anyone know why this could be, hopefully it's something easy that I may of missed. I have seen the Traxxas TRX 6545 listed, but it's not in stock and there's not much information about them either.