Have you ever considered how many times in a day you make use of a battery? You pick up your mobile phone and it has a battery, you start you car and the engine fires up because of a battery, you’re at a work meeting and your laptop is running off a battery, you look at your wristwatch and it has a battery – you may even have one in your razor or toothbrush. Batteries are ubiquitous sources of power in our lives and make our daily functioning easier and more convenient. They do also however need to be charged in order to be of use to us.
Count Alessandro Volta was the Italian physicist who bought the wonderful world of battery power to life. He created a simple battery in 1799 from zinc and silver metal plates and brine-soaked paper known as the voltaic pile that was the first device to emit a steady current. In recognition of Volta’s discovery the SI unit of electromotive force, electric potential and electric potential difference became known as the Volt. Voltages of commonly used items include car batteries 12 V, single, non-rechargeable alkaline batteries 1.5 V and household mains 230 V. To maximize the use of the electrical charge produced by a battery it must be connected to a load, for example a motor or an electric circuit.
Batteries require anodes, cathodes and electrolytes to produce a current involving an electrochemical reaction that moves electrons from negative to positive terminals and come in both non-rechargeable and rechargeable forms. To restore the charge in the rechargeable battery, energy must be supplied from an external source, for example via a battery charger, that moves the electrons in reverse from positive to negative terminals, thereby restoring the charge. Lithium-ion (LiOn), nickel-metal hydride (NiMH) and nickel-cadmium (NiCd) batteries are examples of rechargeable batteries. The charging process however is not a hundred percent efficient so gradually charge is lost and the battery will eventually cease to function.
Batteries are broadly divided into three categories namely industrial, automotive and portable types where the industrial types can be of any size but designed exclusively for industrial or professional use as opposed to portable types that are used in laptops, mobile phones and MP3 players. Industrial batteries can be used as a source of power in forklifts, golf carts, lighthouses, professional video equipment and mobility buggies. More interesting applications for batteries are in medical science, asset tracking equipment, uninterruptible power supplies and in the aerospace industry. Next time you have a moment, picture what our world would look like if we had to walk around with everything plugged into a socket.