Which terminal should be disconnected first when removing a 12-volt battery to minimize sparking?

• A. Positive terminal
• B. Negative terminal
• C. Both terminals at once
• D. It doesn't matter

Answer: (B)

When removing a 12-volt battery, the goal is to interrupt the circuit in a way that minimizes an arc. In most vehicles, the negative terminal is bonded to the chassis and serves as the ground path. Disconnecting the negative first breaks that return path to the battery. If the positive terminal is loosened while the negative is still connected, a tool or metal object could briefly bridge positive to ground and create a noticeable spark. Once the negative is off, loosening the positive is much less likely to spark because there’s no complete circuit back to the battery. Disconnecting only the positive first or trying to remove both at once increases the chance of arcing.