Two physicists, Luigi Galvani (1737-1798) and Alessandro Cont di Volta (1745-1827) were the first scientists to study electricity. Because these two scientists were pioneers words like ‘galvanic element’ and ‘volt’ were named after them. They first observed the effects of electricity on living creatures by using just a simple machine producing static electricity. In 1780, Cont di Volta manufactured the first simple battery. The construction was very simple and consisted of zinc and copper discs placed on top of each other separated by cloth or cardboards soaked in brine (electrolyte). The Voltaic Pile produced electricity when the discs were connected with a wire. Over the years and with the technological evolution this Voltaic Pile evolved as the man's need for energy was constantly growing.
Batteries are categorized into primary and secondary.
Primary batteries are used in electrical appliances, photographic equipment, watches, computers and various other devices in everyday life.
Most primary batteries are cylindrical, flat or knob - shaped (buttons) with a capacity below 20 Ah. They are usually used in households, as opposed to secondary batteries which are usually used in industries. The main types of primary batteries are:
- Zinc / Carbon (Zn / C): the most widely known simple battery. For simple use and with the shortest life span.
- Zinc / Chloride (Zn / Cl): with a little longer life span. Used where there are greater demands for energy.
- Alkaline Manganese: even longer life span than the previous two types. They are more environmentally friendly.
- Silver knob: usually contains silver oxide, mainly used in watches.
- Lithium: long-lived, contains metallic lithium and are widely used in photographic equipment and mobile phones.
- Zinc - Air: another battery type with the innovation that instead of having a positive pole, atmospheric oxygen is used.
- Mercury: with mercuric oxide, mainly used in medical devices such as headsets for hardness of hearing.
Primary batteries are easy and simple to use, and they have few maintenance requirements. In addition, they are available in different shapes and sizes to fit in any appliance. Finally, they have reliability and acceptable costs combined with a good life span, energy density and power.
Secondary electric batteries are electrically recharged and can be used almost anywhere. They are divided into three basic types:
- Rechargeable system nickel - cadmium (Ni-Cd): The first rechargeable batteries ever made. Used in electric tools, mobile phones, laptops, games, etc., with a lifetime of 4-5 years. Unfortunately, cadmium is Hazardous. Consequently, efforts are being made to have this material removed from the market and wherever possible to be substituted with other materials.
- Rechargeable lead System (Pb): Their discovery revolutionized the automobile industry, since most car batteries belong to this category. Unfortunately, lead is also Hazardous for the environment, so it is essential to collect the empty batteries from the garages and send them for recycling.
- Nickel - Metal Hydride (NiMH): System more environmentally friendly than Ni-Cd which they tend to replace and with a longer life span.
Rechargeable batteries have several advantages, economically, environmentally and technologically. The same battery can be used several times, depreciating the acquisition costs very quickly. They operate at high and low temperatures and they also have very high performance in most of their operational life.
Some of the appliances and tools we use in our everyday life and require batteries for their operation are:
Toys (radio control, dolls, etc.)
Electric drill and other hand tools
Headphones for hardness of hearing
Remote Controls etc
These are just a few of those appliances with batteries that we use in our homes. In fact, most of batteries are used in industries and business, for portable appliances which are needed for different applications. Also, batteries are still used in the production of electricity (accumulators) storing the stream until it is delivered to our homes.