Why disconnect a vehicle battery before repairs?

• A. To make the battery smile
• B. To prevent battery from charging while working
• C. To cool the battery
• D. To prevent electrical shock or accidental deployment of airbags

Answer: (D)

Safety from electrical energy is the priority when working on a vehicle, especially with airbags. The battery powers the airbag system and related wiring, so if you leave the battery connected while you’re performing repairs, a short or stray contact could suddenly energize the airbag inflator and cause deployment, which can injure you or bystanders. Disconnecting the battery removes that power source, greatly reducing the risk of accidental airbag deployment and also lowering the chance of electrical shock if tools or conductors come into contact with live circuits. While you might hear that this also stops charging or protects components in some scenarios, the core safety reason is to eliminate the power that could trigger airbags or shocks during work.