When disconnecting a vehicle's battery cable, which cable should be disconnected first to ensure safety?

Disconnecting the negative cable from the battery first is an essential safety practice. Doing so prevents accidental short circuits that can occur if a tool or other conductive object bridges the positive terminal of the battery and the vehicle's metal chassis or engine block while the positive cable is still connected.

The negative battery cable is connected to the vehicle’s ground, and by removing it first, you effectively isolate the battery from the entire electrical system of the vehicle. This significantly reduces the risk of electric shock and minimizes the potential for sparking, which is especially important in scenarios where flammable gases might be present around the battery.

In contrast, if the positive cable were to be removed first, any contact between the positive terminal and the vehicle's structure while the negative terminal is still connected could lead to a short circuit, which could damage components or even cause fire hazards. Therefore, maintaining this order—disconnection of the negative cable followed by the positive—ensures a safer working environment when handling automotive batteries.