The negative terminal on a car battery is almost always black and is marked with a minus sign (-). The positive terminal is typically red and has a plus sign (+). This color-coding and symbol system is a universal standard in the automotive industry designed to prevent dangerous mistakes during connections, such as when jump-starting a car.
Connecting jumper cables incorrectly can cause severe damage to the vehicle's electrical system, destroy the battery, or even create a spark that ignites battery gases. To be absolutely certain, you should always look for the identifying symbols stamped directly on the battery case next to each terminal. The negative terminal is also usually connected directly to the vehicle's metal chassis or engine block, which is known as "grounding."
Here is a quick reference table for identifying battery terminals:
| Identification Method | Negative Terminal | Positive Terminal |
|---|
| Cable Color | Black | Red |
| Terminal Symbol | Minus Sign (-) | Plus Sign (+) |
| Physical Connection | Often bolted to chassis/engine | Connected to starter/solenoid |
| Multimeter Test (to chassis) | 0 Volts | +12.6 Volts |
| Terminal Size (some imports) | Smaller diameter | Larger diameter |
When working with a battery, always connect the positive cable first when installing or jump-starting, and disconnect the negative cable first when removing the battery. This minimizes the risk of a short circuit. If the terminals are corroded or the colors are faded, rely on the engraved symbols for a definitive identification. Your safety and the health of your car's electronics depend on getting this simple step right.
