A battery is a device that produces electrons through electrochemical reactions and contains positive (+) and negative (-) terminals. A battery consists of one or more electrochemical cells, which transform stored chemical energy directly into electrical energy. When an external load connects to a battery, electrons cross from the negative to the positive terminal, creating an electrical current. This current may power a motor, a light bulb, a clock, a computer, a cellphone, and other electronic devices or equipment. Battery flow speed is determined by the battery’s internal resistance and outside load.