Hearing Aid Batteries

In science and technology, a battery is a device that stores chemical energy and makes it available in an electrical form. Batteries consist of electrochemical devices such as one or more galvanic cells, fuel cells or flow cells. more...

Home
Bath & Body
Dietary Supplements,...
Hair Care
Hair Removal
Health Care
Massage
Medical, Special Needs
Bathroom Safety
Braces, Supports
Hearing Assistance
Hearing Aid Batteries
Hearing Aids
Other
Incontinence Aids
Mobility Equipment
Monitoring, Testing
Orthotics, Insoles
Other
Positioning Equipment
Respiratory Aids
Nail
Natural Therapies
Oral Care
Other Health & Beauty Items
Skin Care
Tattoos, Body Art
Vision Care
Weight Management
Wholesale Lots

The earliest known artifacts that may have been batteries are the Baghdad Batteries, from some time between 250 BC and 640 AD. The modern development of batteries started with the Voltaic pile, announced by the Italian physicist Alessandro Volta in 1800. The worldwide battery industry generates US$48 billion in sales annually (2005 estimate).

In older word usage an electrical "battery" is an interconnected array of similar voltaic cells ("cells"). That distinction, however, is usually considered pedantic in most contexts (other than the expression dry cell), and in current English usage it is more common to call a single cell used on its own a battery than a cell.

How batteries work

A battery is a device in which chemical energy is directly converted to electrical energy. It consists of one or more voltaic cells, each of which is composed of two half cells connected in series by the conductive electrolyte. In the figure to the right, the battery consists of one or more voltaic cells in series. (The conventional symbol does not necessarily represent the true number of voltaic cells.) Each cell has a positive terminal, shown by a long horizontal line, and a negative terminal, shown by the shorter horizontal line. These do not touch each other but are immersed in a solid or liquid electrolyte.

The electrolyte is a conductor which connects the half-cells together. It also contains ions which can react with chemicals of the electrodes. Chemical energy is converted into electrical energy by chemical reactions that transfer charge between the electrode and the electrolyte at their interface. Such reactions are called faradaic, and are responsible for current flow through the cell. Ordinary, non-charge-transferring (non-faradaic) reactions also occur at the electrode-electrolyte interfaces. Non-faradaic reactions are one reason that voltaic cells (particularly the lead-acid cell of ordinary car batteries) "run down" when sitting unused.

Voltaic cells, and batteries of voltaic cells, are rated in volts, the SI unit of electromotive force. The voltage across the terminals of a battery is known as its terminal voltage. The terminal voltage of a battery that is neither charging nor discharging (the open-circuit voltage) equals its emf. The terminal voltage of a battery that is discharging is less than the emf, and that of a battery that is charging is greater than the emf.

Alkaline and carbon-zinc cells are rated at about 1.5 volts, because of the nature of the chemical reactions inside. Because of the high electrochemical potentials of lithium compounds, Li cells can provide as much as 3 or more volts. However, lithium compounds can also be hazardous.

Read more at Wikipedia.org