Identifying battery positive and negative terminals comes down to three reliable methods: the + and – symbols stamped on the casing (always accurate), color coding (red = positive, black = negative for most automotive and industrial applications), and physical size or shape. Identifying battery positive and negative terminals comes down to three reliable methods: the + and – symbols stamped on the casing (always accurate), color coding (red = positive, black = negative for most automotive and industrial applications), and physical size or shape. When assembling the battery cabinet, pay attention not to touch the positive and negative poles of the battery at the same time during installation. During installation, the positive pole is connected to the negative pole and installed in series. At its core, battery terminal polarity is the manifestation of an electrical potential difference.