Rechargeable batteries

Rechargeable batteries are batteries in which chemical reactions can be reversed by supplying electrical energy, allowing them to be used again.

• While a battery powers a device, stored chemical energy changes into electrical energy. During charging, electricity from a charger drives the chemicals back towards their original state.
• Think of one as a water bottle: using the battery is like drinking the water, and charging it is like refilling the bottle. The bottle can be refilled many times, but it gradually becomes less useful if it gets worn or damaged.
• A full use followed by a recharge is called a charge–discharge cycle. Each cycle causes tiny chemical changes inside the battery, so its ability to store energy slowly decreases.
• Different rechargeable batteries use different chemicals. Lithium-ion batteries are popular because they can store a lot of energy for their size, which makes them useful in phones, tablets, and electric vehicles.
• Rechargeable batteries should be charged with the correct charger and taken to an e-waste collection point when no longer usable. Their materials can be recovered, and safe recycling prevents harmful substances from entering soil and water.