SAFETY FIRST
Have you ever seen a crusty, white powder on a battery? Don’t touch it; it’s a chemical leak. The reactions inside standard batteries create hydrogen, a gas. Over time this gas can build up, causing the pressure inside the battery to rise. Then, pop! The outer casing bursts. Potassium hydroxide leaks out of the battery and reacts with carbon dioxide in the air to form potassium carbonate. This is the crusty white stuff, which looks a bit like salt. Potassium carbonate isn’t dangerous to touch, but potassium hydroxide can burn your skin. Always take care when disposing of leaky batteries.