I'm trying to jump start my car with a portable booster pack, the car has been out for about 2 weeks in temperatures that regularly reach -15 C and the battery is completely dead. It's a brand new battery I bought a month ago. Normally when I place the cables on positive and negative, I get a clicking sound and the LEDs on the booster start pulsing. I don't get that now, and the battery doesn't charge, unless I engage the manual override on the booster. Is this a consequence of the cold weather? What can I do to start my car? As it stands the booster does nothing but drain itself out and power the dash/lights.
The booster pack with manual override sounds like it is working fine. However, something on your car is trying to kill it just like it tried to kill your new battery. Like a heavy short circuit or a bad starter. Disconnect the negative battery post (or remove the battery completely) and charge it fully. Then you need to isolate and fix the electrical fault.