Ci - Rated capacity
in ampere-hours for a specific, constant discharge current (where i is the
number of hours the cell can deliver this current). For example, the
C5 capacity is the ampere-hours that can be delivered by a cell at
constant current in 5 hours. As a cell's capacity is not the same at all
rates, C5 is usually less than C20
for the same cell.
- An alloy of calcium metal and lead wherein the calcium contents is usually under 0.10%.
- A metal (Cd) used as a reference electrode for determining the individual positive and negative plate potentials as distinguished from the cell potential.
- Lead oxide which has been manufactured by heating lead to a relatively high temperature.
- The quantity of electricity delivered by a battery under specified conditions, usually expressed in ampere-hours.
- 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.
- Box for holding the cell element and the electrolyte.
- The electrode towards which positive ions flow. It is considered the positive in a primary cell.
- An alkali solution (NaOH) formerly used in treating wooden separators.
- An individual unit of a battery consisting of a container, electrode pack and electrolyte.
- The conversion of electrical energy, provided in the form of a current from an external source, into chemical energy within a cell or battery. This is the opposite of a discharge.
- The current applied to a secondary cell or battery to restore its capacity. This rate is commonly expressed as a multiple of the rated capacity of the cell or battery.
For example, the C/10 charge rate of a 500-Ah cell
or battery is expressed as:
C/10 rate = 500 Ah / 10 h = 50
- Complete path taken by a current of electricity from its source back to its source.
- A charge whose primary purpose is to obtain a thorough mixing of the strong filling acid and the weak electrolyte retained by the electrodes in a lead-acid battery.
- The characteristic of a material of conducting an electric current expressed in terms of reciprocal ohms (mhos) per unit cross-section and per unit length.
- The relative stiffness or plasticity of a battery paste.
constant potential charge
- Charging technique whereby the current rate is allowed to drop automatically as the battery voltage builds up to a pre-set voltage.
constant rate charge
- Charging technique whereby the current rate is kept constant by varying the outside resistance.
- See case.
- Formation of electrodes with separators in place in the cell container.
- Disintegration of electrode grids due to electrochemical attack (for example, the conversion of metallic lead grids to lead dioxide in lead-acid cells).
- Unit of electric charge, equivalent to one ampere for one second (or an ampere-second).
- Voltage of a cell or battery opposing the voltage of the charging line.
- The apparent density of a paste (in lead-acid batteries) expressed in terms of grams per unit volume.
- The flow rate of electricity (expressed in amperes).
- An inert member of high electrical conductivity used to conduct current from or to an electrode during discharge or charge.
- Current per unit area (expressed in amperes per unit area).
- Battery voltage reached at the termination of a discharge.
- The discharge and subsequent charge of a secondary cell such that it is restored to its original conditions.
cycle life - The
number of cycles under specified conditions which are available from a
secondary battery before it fails to meet specified criteria as to
- Withdrawal of at least 80% of the rated capacity of a cell.
- Weight of a substance per unit volume (usually expressed in grams per cubic centimeter).
- A reduction in the polarization of an electrode.
- A substance of means used to prevent or decrease polarization. The term "depolarizer" is often used to describe the positive electrode of a primary cell.
depth of discharge - The ratio of the
quantity of electricity, usually expressed in ampere-hours, removed from a
secondary cell on discharge to its rated capacity.
- Momentary immersion of freshly pasted plates in dilute sulfuric acid solution (for lead-acid batteries).
direct current (dc)
- Current of unidirectional flow.
- The conversion of the chemical energy of a cell into electrical energy and withdrawal of the electrical energy into a load.
discharge rate - The current during
discharge of a cell. This can be expressed in amperes, but more commonly it is
normalized to rated capacity (C), and expressed as Ci/X,
where i is the hour rate for the rated capacity, and X is a time
specification, usually in hours. For example, the 10-hour discharge rate of a
500-ampere-hour cell (rated at the 5-hour discharge rate) is expressed
= 50 amperes = C5/10 rate.
- Waste product or impurities formed on the surface of molten metal.
- A cell with immobilized electrolyte. The term "dry cell" is often used to describe the Leclanché cell.
dry charged battery
- A dry battery with the plates in an essentially fully charged state and able to deliver a current when filled with electrolyte.
- Removal of water from pasted plates and separators.