Battery systems are devices that store and provide electrical energy for various applications. They consist of one or more electrochemical cells that convert chemical energy into electrical energy. Common types of battery systems include lithium-ion, lead-acid, and nickel-metal hydride, each with unique characteristics and uses. These systems are widely used in everyday items like smartphones, laptops, and electric vehicles. They play a crucial role in renewable energy storage, allowing excess energy from sources like solar panels to be stored for later use. Battery systems are essential for powering modern technology and supporting sustainable energy solutions.