Anode
The electrode in an electrochemical cell where oxidation takes place. During discharge, the negative electrode of the cell is the anode. During charge, the positive electrode is the anode.

Battery or Pack
Technically, two or more electrochemical cells electrically interconnected in an appropriate series/parallel arrangement to provide the required operating voltage and current levels. Frequently, however, the term "battery" is applied to a single cell.

Bobbin
A cylindrical cell design utilizing an internal cylindrical electrode and an external electrode arranged as a sleeve inside the cell container.

Capacity
The total number of ampere-hours or watt-hours that can be withdrawn from a fully charged cell or battery under specified discharge conditions.

Cathode
The electrode in an electrochemical cell where reduction takes place. During discharge, the positive electrode of the cell is the cathode. During charge in a rechargeable battery, the negative electrode is the cathode.

Cell
The basic electrochemical unit used to generate or store electrical energy.

Constant Current
A battery discharge regime whereby the current drawn during the discharge remains constant.

Cutoff Voltage
The battery voltage at which the discharge is terminated. The cutoff voltage is specified by the battery manufacturer and is generally a function of discharge rate.

Cylindrical Cell
A cell in which the positive and negative plates are rolled up and placed into a cylindrical container (as opposed to stacking the plates in a prismatic cell design).

Discharge
The change from chemical energy of a battery into electrical energy, and the withdrawal of the electrical energy into a load.

Discharge Rate
The rate, usually expressed in amperes, at which electrical current is taken from the battery.

Drain
The current withdrawn from a battery during discharge.

Electrode
The site, area or location at which electrochemical processes occur.

Electrolyte
The medium that transports the ions carrying the charge between the electrodes during the electrochemical reaction in a battery.

Energy
The output capability of a cell or battery expressed in watt-hours.

Fuse
A safety device used for cutting off an electrical current in the event of an abusive condition.

Internal Impedance
The opposition exhibited by a circuit element (cell or battery) to the flow of an alternating current (A.C.) of a particular frequency as a result of resistance, induction and capacitance.

Internal Resistance (IR)
The opposition exhibited by a circuit element (cell or battery) to the flow of direct current (D.C.). In a cell, the internal resistance is the sum of the ionic and electronic resistances of the cell components.

Limiting Current
The maximum current drain under which the particular battery will perform adequately under a continuous drain. The rate is based on whatever drain rate reduces the running voltage to 1.1 volts.

Lithium Battery
Lithium primary batteries (non-rechargeable) offer high energy density, extremely long shelf life (two to three times that of Alkaline), a wide operating temperature range, and excellent durability. Lithium primaries are available in many chemistries, each with their own particular attributes.

Lithium Manganese Dioxide Battery (LiMnO2)
A primary battery (non-rechargeable), the Lithium Manganese Dioxide battery offers high energy density, reliability and excellent shelf life. Less volatile and less costly than Lithium Sulfur Dioxide, LiMnO2 batteries offer a good balance of performance and safety. Their uses include keyless entry systems and memory back up.

Lithium Thionyl Chloride Battery (LiSOCl2)
A primary battery (non-rechargeable), the Lithium Thionyl Chloride battery has the highest energy density of all Lithium types. Service life is typically 15 to 20 years. These cells are best suited for applications having low continuous-current and moderate pulse-current requirements. Their long service life and low self-discharge rate make them ideally suited for use in harsh or inaccessible environments like utility monitoring and electronic toll collection.

Load Current
The discharge current delivered to a battery-powered device.

Milliampere-hour (mAh)
A battery capacity or rating. A battery that provides a current of 1000mAh for one hour is rated at 1000mAh (or 1 Ah).

Negative
An electrode or a terminal that has an excess of electrons.

Nominal Voltage
The characteristic operating voltage or rated voltage of a battery.

Ohm
A measure of electrical resistance that causes one volt to produce a current of one ampere.

Open-Circuit Voltage (OCV)
The difference in potential between the terminals of a cell when the circuit is open (no-load condition).

Parallel
The interconnection of cells or batteries where all the like terminals are connected together. This results in increased capacity.

Passivation
The phenomenon by which a metal, in conditions of thermodynamic instability, remains unattacked because of modified or altered surface conditions.

Polarity
In electricity, the quality of having two charged poles, one positive and one negative.

Positive
A terminal or electrode that has a shortage of electrons.

Positive Temperature Coefficient (PTC)
A PTC device protects the cell or battery from external short circuits while allowing it to continue functioning after a short circuit is removed.

Primary Battery
A battery which is not intended to be recharged and is discarded when it has delivered all of its electrical energy. (A non-rechargeable battery.)

Prismatic Cell
The positive and negative plates are stacked rather than rolled as done in a cylindrical cell.

Pulse Current
A periodic current drain of higher than normal drain rates.

Rated Capacity
The number of ampere-hours a battery can deliver under specific conditions (for example, rate of discharge, end voltage, temperature). Rated capacity is usually specified by the battery manufacturer.

Resistance
The degree to which the flow of electrons is opposed by the material the electrons must pass through. Resistance is expressed in ohms.

Safety Vent
A safety mechanism designed into a cell that activates under specific conditions of abuse to relieve internal pressure.

Self-Discharge
The loss of capacity of a battery during storage due to internal chemical action.

Series
The interconnection of cells where the positive terminal of the first is connected to the negative terminal of the second, and so on. This results in increased voltage.

Shelf Life
The duration a cell can be kept in storage under specified conditions and still retain its ability to give a specified performance.

Short Circuit
An unwanted electrical connection between a negative and positive source. Short circuits can damage the battery and equipment and can cause fire.

Spiral Wound
An electrode structure of high surface area created by winding the electrodes and separator into a spiral, jelly-roll configuration.

Temperature Cutoff
A safety device which senses temperature in a battery and opens or cuts off the electrical circuit if the specified temperature is exceeded, thus preventing a further rise in temperature.

Terminal
A device at the end of a cell or wire at which a connection to an adjoining cell or wire is established or broken.

Thermistor
A temperature sensitive resistor usually made from specially processed oxides that are used to sense end of charge temperature rises and terminate high rate charging.

Voltage
A unit of measuring electric potential. Voltage is the difference in electrical energy between two points.

Voltage Delay
Time delay for a battery to deliver the required operating voltage after it is placed under load.