Appendix B. Definitions
- Ratio of electrical output of a battery to the input required to fully recharge it under specified conditions (expressed in percentage).
- The system of active materials within a cell that provides electrical energy storage through an electrochemical reaction.
- The site, area, or location at which electrochemical processes take place.
- The medium which provides the ion transport mechanism between the positive and negative electrodes of a cell.
- Potential causing electricity to flow in a closed circuit.
- That part of an atom having a negative charge.
- (1) A substance which cannot be separated into other substances.
(2) Electrode and separator assembly in a cell.
end of life
- The stage at which the cell meets specific failure criteria.
- The prescribed voltage at which the discharge (or charge, if end-of-charge voltage) of a cell may be considered complete (also cutoff voltage).
- Energy per unit weight or volume. (Wh/kg or Wh/L)
- A cement used to seal battery cases or plastic battery parts together. Often supplied as a two or three part mix.
- The process of restoring all cells in a battery to an equal state of charge.
- The difference in potential between an electrode and an electrolyte when they are in equilibrium for the electrode reaction which determines the electrode potential.
- Composition of an alloy which has the lowest melting point of any other composition. For example, antimonial lead alloy containing approximately 3 - 13 percent antimony.
- Under equilibrium conditions, the forward and backward currents of an electrochemical process are equal. This equilibrium current is defined as the exchange current.
expander - Additional agent in negative
electrode pastes, the function of which is to increase capacity on high rate
and low temperature discharges and to extend negative plate useful
- See pasted plate.
- Discharge cutoff voltage.
- The current specified for completing the charging of a cell that is nearing the fully charged condition.
- The removal of surface moisture from freshly pasted plates.
- A method of maintaining a cell in a charged condition by continuous, long-term constant-voltage charging, at a level sufficient to balance self-discharge.
- A cell design which incorporates an excess amount of electrolyte.
- Electrochemical conversion of electrode materials to the active state.
- Discharging a cell, with external battery or power source, below zero volts into voltage reversal.
- Electrochemical processing of a battery plate or electrode between manufacture and first discharge which transforms the active materials into their usable form.
frame - Outside bars of a grid forming the
- Lead sulfide ore (PbS) from which virgin lead is obtained.
- The evolution of gas from one or more of the electrodes in a cell. Gassing commonly results from local action (self-discharge) or from the electrolysis of water in the electrolyte during charging.
- A cell in which the electrolyte has been immobilized by converting it into a gel-like mixture.
- Thin sheet of glass fibers held in place by means of a bonding agent and placed against a positive plate(in lead-acid batteries).
- A framework for a plate or electrode which supports or retains the active materials and acts as a current collector.
- Those portions of a separator bounded by the ribs.
group - An assembly of plates of like polarity
burned to a common strap.
- (1) Agent added to a paste mix in order to increase plate strength. (2) One of the components of an epoxy system.
- Antimonial lead alloy.
- A quantitative term indicating a discharge rate that is usually greater than the Ci/1 rate, e.g., 2Ci rate, where i is an integer denoting the rate at which C was determined.
- Batteries requiring an operating temperature much higher than ambient temperature (i.e., greater than 100ºC).
hydrometer - A floating instrument used to
determine the specific gravity of liquids.
immobilized electrolyte - Electrolyte
whose viscosity has been increased to
the point where it will no longer flow. Electrolyte may also be immobilized in an absorptive glass mat.
- The apparent resistance in an ac circuit.
- The opposition to the flow of an alternating current at a particular frequency in a cell at a specified state-of-charge and temperature.
- The opposition or resistance to the flow of a direct electric current within a cell; the sum of the ionic and electronic resistances of the cell components. Its value may vary with the current, state-of-charge, age, and temperature.
ion - Part of molecule or group of atoms,
positively or negatively charged, which transports electricity through the
joule - Unit of energy, equal to a
watt-second (a newton-meter).
- Finely divided carbon used as part of the negative plate expander (in lead-acid batteries).
- A higher oxide of lead present in charged positive plates and frequently referred to as lead peroxide.
- A lead salt formed by the action of sulfuric acid on lead oxide during paste mixing and formation. It is also formed electrochemically when a battery is discharged.
- A lead oxide used to prepare paste mixes.
local action - Electrolytic discharge of active
materials caused by contaminants in localized spots of a charged electrode,
and contributing to self-discharge.