The positive on a car battery is typically given a red color, while the negative is black. These could be the actual poles themselves or an indicator around the poles. For the most part ...

connect the positive battery terminal to the 7805 input pin, the positive usb pin to the 7805 output pin, and connect the negative battery terminal and the usb ground pin to the 7805 ground pin.

Choose a jumper pack To choose a jumper pack ... you would ordinary jumper cables—positive clamp to the positive battery post and negative clamp to the negative battery post or a metallic ...