Under no circumstances should what type of brush be used for cleaning batteries?

• A. Wire brush
• B. Nylon brush
• C. Bronze brush
• D. Brass brush

Answer: (A)

The type of brush you should never use on batteries is a wire brush. Its metal bristles can bridge battery terminals or shed metal fragments into the electrolyte, creating a short, arcing, or contaminating the terminals. Hydrogen gas emitted by batteries makes sparks especially dangerous around cleaning activities. Non-metallic brushes, like nylon, are preferred because they scrub away corrosion without introducing conductive particles. Metal brushes such as bronze or brass are still risky for the same reason, but the primary hazard with a wire brush is the direct risk of shorting and sparks.