Rechargeable

Rechargeable refers to energy storage devices that can be restored to full capacity through electrical charging after discharge. The term is most commonly applied to rechargeable batteries, which convert chemical energy into electrical energy and vice versa in a reversible reaction. Rechargeable cells enable multiple cycles of use, reducing waste and the cost per unit of energy compared with disposable cells.

Common rechargeable chemistries include lithium-ion (Li-ion), nickel–metal hydride (NiMH), nickel–cadmium (NiCd), and lead-acid. Li-ion cells are widely used in portable electronics and electric vehicles due to high energy density and light weight, while NiMH and NiCd have historically served portable devices and power tools, with NiCd declining because of memory effects and cadmium toxicity. Lead-acid remains inexpensive for automotive starting-lighting-ignition and stationary backup power. Emerging solid-state and lithium-sulfur chemistries aim to improve safety and energy density.

Performance depends on cycle life, depth of discharge, temperature, and charging regime. The number of full charge–discharge cycles varies by chemistry and design. Depth of discharge and high temperatures shorten life; appropriate chargers and battery-management systems are used to monitor voltage, current, and temperature to prevent overcharging and thermal runaway.

End-of-life handling emphasizes recycling to recover materials such as lithium, cobalt, nickel, and lead. Recycling reduces environmental impact and supports resource sustainability. Rechargeable technologies underpin many modern conveniences, from smartphones and laptops to electric vehicles and large-scale energy storage.