Book 3, Question 27
Why Do Batteries Die?
A battery stores energy in chemicals. When you use it, those chemicals change. When the useful chemicals run out, the battery dies.
From the book
Page from A Million Whys Book 3
More fun facts
- Batteries store energy as chemical energy and turn it into electricity when you use them.
- Charging a rechargeable battery turns electricity back into stored chemical energy.
- Batteries were invented in 1800, but scientists are still studying the complex chemistry inside them.
- The chemical changes inside a battery never reverse perfectly. Over many charges, this slowly changes the battery's materials and lowers how well it works.
- Lithium-ion batteries power much of modern life, from phones to laptops, because they can store a lot of energy.
- Scientists are still searching for new battery materials that could store much more energy.
Sources: U.S. Department of Energy, Science News Explores, Scientific American
Questions kids ask
Why do rechargeable batteries wear out?
Each time they charge and drain, the chemical changes inside do not fully reverse. Over time this changes the battery's materials, so it holds less energy.