Glossary of Battery Terms
Source of electrical energy obtained by the direct conversion of chemical
energy and not designed to be charged by any other electrical source.
Rechargeable battery (Secondary battery):
Source of electrical
energy obtained by the direct conversion of chemical energy designed to be
charged by any other electrical source. It is also called a storage
battery or accumulator.
circuit voltage (OCV):
Voltage across the terminals of a battery when no external current is
circuit voltage (CCV):
Voltage across the terminals of a battery when it is on discharge.
As a battery has an internal resistance, CCV is lower than OCV and CCV
becomes lower with a range of current.
Suitable approximate value of voltage used to identify the voltage of a
battery. For example): Alkaline manganese battery; 1.5V, Lithium manganese
dioxide battery; 3.0V
External device or
method through which a battery is discharged.
End-point voltage (End voltage, Cutoff voltage, Final voltage):
Specified closed circuit voltage at which a service output test is
Resistant component in
a battery that makes discharge reaction slow.
Operation during which a battery delivers current to an external circuit.
Continue to discharge after a battery voltage drops below its end-point
Decreasing capacity during storage without load, caused by chemical
reaction in a battery. The higher the temperature during storage, the
greater the rate of self discharge.
Discharge characteristics (Discharge curve):
Change of a battery
voltage with discharge.
Operation during which a reverse reaction of discharge occurs when
electrical energy is received from an external source.
Voltage deviation from equilibrium caused by charge or discharge.
Duration time (Duration period ):
Time until a battery
voltage exceeds the end-point voltage during discharge.
Capacity (Ah, mAh) is the product of the discharge current (A, mA) and
discharge time (h). Note: Because manganese dry batteries and alkaline manganese batteries are
often used for heavy-duty applications, the discharge time at a specific
load is usually mentioned instead of the capacity.
Usable energy of a battery per unit volume or unit weight. The former is
called volumetric energy density (Wh/l); the latter gravimetric energy
Test conducted within 2 months of the production month.
the battery under specified conditions.
Test conducted within 2 weeks after storage.
finished or semi-finished battery is store under specified conditions for
a specified period.
Expiration of guarantee period of a primary battery determined by each
manufacturer conforming to the IEC. Because a secondary battery can be
used over again by charging, it is unnecessary to show this.
(International Electrotechnical Commission) is a worldwide organization of
standardization comprised of all national electrotechnical committees.
Electrode materials in a battery which cause an electrochemical reaction
to generate electricity. See chart below.
Medium in a battery which causes ions to move to create an electrochemical
reaction. Either water or non-aqueous solution is used as solvent. The
latter is called non-aqueous electrolyte solution, either organic or
Ratio of usable capacity against theoretical capacity.
characteristics against leakage.
Surges of current
across the terminals of a battery when it is short-circuited.
Internal short circuit:
electrically between the positive electrode and negative electrode caused
by damage to the separator or gasket, or the presence of a conductor
piercing the separators. A battery will become completely exhausted before