Do not burn old flashlight batteries

Popular Science once recommended throwing old batteries in the fire because "the burning zinc may help prevent soot formation, and the metals and chemicals make colorful flames." The November 1951 tip was bad advice, writes Snopes, but not so bad then as now: batteries a half-century ago contained different chemicals, were unsealed, and less likely to explode.

https://www.youtube.com/watch?v=ZDq8jGXl78k