1. cell—the basic electro-chemical unit to generate or store electrical
2. primary battery—a battery which is not intended to be recharged and is discharged when the battery has delivered all of its electrical energy.
3. secondary battery—a galvanic battery which, after discharge, may be restored to the fully charged state by the passage of an electrical current through the cell in the opposite direction to that of discharge.
4. open-circuit voltage—the difference in potential between the terminals of a cell when the circuit is open (no load condition)
5. working voltage—the typical voltage or range of voltage of a battery during discharge (also called operating voltage or running voltage).
6. nominal voltage—the characteristic operating voltage or rated voltage of a battery.
7. cut off voltage—the battery voltage at which the discharge is terminated. the cut off voltage is specified by the battery manufacturer and is generally a function of discharge rate.
8. capacity 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.
9. capacity—the total number of ampere-hours that can be withdrawn from a fully charged cell or battery under specified conditions of discharge.
10. 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.
11. internal resistance—the opposition exhibited by a circuit element to the flow of direct current (dc.). in a cell, the internal resistance is the sum of the ionic and electronic resistances of the cell components.
12. self discharge—the loss of useful capacity of a battery on storage due to internal chemical action (local action).
13. discharge rate—the rate, usually expressed in several rated capacity at which electrical current is taken from the battery.
14. charge rate—the rate, usually expressed in several rated capacity at which electrical current is charged into the battery.
15. constant voltage charge—when charging, a method to keep constant voltage to charge the battery.
16. constant current charge—when charging, a method to keep constant current to charge the battery.
17. trickle charge—a charge at a low rate, balancing losses through local action and periodic discharge, to maintain a battery in a fully charged condition.
18. memory effect—a phenomenon in which a cell or battery operated in successive cycles to the same, but less than full, depth of discharge temporarily loses the rest of its capacity at normal voltage levels.
19. leakage—the inner electrolyte penetrates to its metal can, which makes its appearance dirty and pollutes the environment.
20. battery or pack—two or more electro-chemical cells interconnected in an appropriate series/parallel arrangement to provide the required operating voltage and current levels. under common usage, the term “battery” is often also applied to a single cell.
21. current drain—the current withdrawn from a battery during discharge.
22. safety vent—a venting mechanism designed into a cell which activates under specific conditions of abuse to relieve internal pressure.