Capacity Retention (or Charge Retention) - The fraction of the full capacity available from a battery under specified conditions of discharge after it has been stored for a period of time.
Internal Resistance (IR) - The opposition exhibited by a circuit element 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.
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.
Hazardous Waste - Waste which is classified as "hazardous" (i.e., potentially harmful to the environment) by the government.
Redundancy (standby) - UPS configuration in which one or several UPS units operate on stand-by, with no load or only a partial load, and can immediately back up a faulty UPS unit by no-break transfer of the load, carried out by a static switch.
Primary Battery - A battery which is not intended to be recharged and is discarded when the battery has delivered all of its electrical energy.
Continuous Test - A test in which a battery is discharged to a prescribed end point voltage without interruption.