Expressions and Terms

What is a Battery?
A battery is a device that generates an electrical current by chemical reaction.

How Does a Battery Work?
Batteries operate on a simple theory: two dissimilar metals in contact with an electrolyte will produce a flow of electrons (electricity) when all elements are in contact with each other.

Categories of Batteries
Batteries fall into two general categories -- primary batteries and secondary batteries.

Primary batteries are batteries that cannot be recharged or "brought back to life" once they have used up their power. Examples of primary batteries include alkaline batteries which are commonly used in flashlights, portable radios, tape and CD players and some medical equipment.

Secondary batteries, also known as storage batteries, are capable of being recharged and reused many times. Lead Acid (used in wheel chairs and biomedical equipment), Nickel Cadmium and Nickel Metal Hydride batteries (used in many portable electronics) are examples of this type.

Battery Chemistries
Following are the six most common cell chemistries, their characteristics and primary uses.

Nickel Cadmium Batteries
Nickel Cadmium batteries, or Ni-Cd as they are commonly called, are rechargeable. They are very suitable for use in small, portable devices such as portable radios, cellular phones, laptop computers and biomedical equipment including monitors, defibrillators and pumps. Ni-Cd's have good load characteristics, are economically priced and are simple to use.

Nickel Metal Hydride Batteries
Nickel Metal Hydride (NiMH) is a rechargeable battery chemistry that is being utilized by many OEMs and is being used to replace Ni-Cd's in many applications. NiMH provides capacity of 25% to 50% higher than Ni-Cd. NiMH has no memory effect (a Ni-Cd problem which decreases voltage levels due to successive recharging without first completely discharging), is environmental friendly (no special recycling regulations) and lighter weight. NiMH is widely used in small, portable devices such as portable radios, cellular phones, laptop computers, etc.

Lead Acid Batteries
Lead Acid batteries are the most common type of secondary or storage battery. Lead Acid batteries are primarily used to power motor vehicles, wheelchairs and biomedical equipment including monitors, defibrillators and pumps, where weight is not a critical factor and low battery cost is desirable.

Lithium Ion
The Lithium Ion (Li-Ion) battery is a very high energy density rechargeable chemistry. It permits building smaller and lighter devices than are possible with Nickel Cadmium (Ni-Cd) and Nickel Metal Hydride (NiMH) batteries. Recently available Li-Ion rechargeable batteries for portable computers and cellular phones have resulted in additional reductions in battery size and weight. Li-Ion is now being designed into a number of portable products such as cellular phones and hand held radios.

Dry Cell Batteries (Alkaline)
Alkaline batteries are primary no rechargeable (disposable) batteries. Available in many different sizes, they are used to power flashlights, toys, portable radios and small biomedical equipment such as recorders and
monitors.

Mercury Batteries
Mercury batteries are primary non rechargeable batteries with very low cost per use and good stability. They last longer than alkaline and zinc-air batteries and are easily recycled through our environmental division. They are commonly used in military, single cell and high heat applications where stability is important.

for more information about batteries and their technologies, please visit http://www.buchmann.ca