which color is positive on a car battery

[JudeAnn]

The positive terminal on a car battery is almost always red and marked with a plus (+) sign. The negative terminal is black and marked with a minus (-) sign. This color-coding and symbol system is a universal standard in the automotive industry designed to prevent dangerous mistakes during installation or jump-starting.

Connecting the battery cables incorrectly can cause severe damage to your vehicle's electrical system, including frying the alternator or engine control unit (ECU), and can even lead to a battery explosion. The red color acts as a critical visual cue for safety. Before you touch any cables, it's a best practice to visually double-check: find the red cable attached to the red, positive terminal.

Beyond color, there are other ways to identify the positive terminal. The positive post is often slightly larger in diameter than the negative post on many batteries. The battery casing itself usually has clear embossed or labeled "+" and "-" symbols. If the colors are faded or covered in corrosion (a white, blue, or greenish powdery substance), these physical markers are your next best reference.

When dealing with a battery where the colors are unclear, follow these steps for absolute certainty:

1. Look for the stamped "POS" or "+" sign on the plastic battery case next to the terminal.
2. Trace the cables. The positive cable almost always leads directly to the starter motor and the vehicle's main fuse box.
3. The negative cable is typically bolted directly to the vehicle's chassis or engine block, which is the ground connection.

Common Battery Terminal Identification Markers	Positive Terminal	Negative Terminal
Primary Color	Red	Black
Symbol	Plus Sign (+)	Minus Sign (-)
Cable Tracing	Leads to starter/fuse box	Bolted to chassis/engine
Post Size (common)	Slightly Larger	Slightly Smaller
Label on Case	"POS" or "P"	"NEG" or "N"

[MacEzra]

Just remember: red is right for positive. It’s the universal rule. The cable is red, and the terminal itself has a plus sign on it. The black one is negative. When you're jump-starting a car, you connect red to red first. Messing this up can get expensive real fast, so that red color is your best friend under the hood.

[LaylaMarie]

Safety is the main reason for the red color. It's a high-visibility warning. Connecting a battery backward sends current the wrong way through sensitive electronics, which can easily destroy them. The red-positive/black-negative standard eliminates guesswork. Always clean any corrosion off the terminals so the colors and symbols are clearly visible before you start any work.