Battery Glossary
Accumulator
An electrochemical device that can transform electrical energy into stored chemical energy and by reversing the process,release energy again.See Secondary battery.
Acid density
The charge state of an automotive battery can be determined by measuring the acid density in kg/l. This is done using an acid siphon.The following characteristic factors apply:Acid density 1.28 kg/l: battery is fully charged.Acid density 1.20kg/l:battery is half charged.Acid density 1.10 kg/l: battery is empty.
Acid level indicator
A component for displaying the level of electrolyte in a cell.
Acid stratification
When charging a lead acid cell,high density acid is produced in the plates.This drops as a result of gravitation to the lower part of the cell.Over repeat cycles in which the electrolyte does not move,a sulfuric acid density gradient is therefore produced.This state must not be allowed to become permanent,otherwise it could irreversibly damage the battery.Possible countermeasures include shaking the battery,increasing the charging voltage and recirculating the electrolyte during cyclical use.
Aging
Abbreviation for Absorptive Glass Mat.This is a mat of micro glass fibers which is used for fixing the sulfuric acid in lead accumulators.
AGM battery
See Maintenance-free battery with fixed electrolyte.
Ambient conditions
Outside influences affecting battery performance and service life,as for example ambient temperature,humidity,vibration,height,effects of shock,etc.
Ambient temperature
The average temperature surrounding the battery.
Ampere (A)
Basic unit of electrical current strength.
Anode
The positive electrode at which oxidation takes place in a liquid solution,i.e. the anions(negatively charged ions)are discharged(loss of electrons).Depending on the current direction,each of the two electrodes can become an anode in secondary cells.The negative electrode is then the anode when discharging.
Ampere-Hours
A unit of electrical measurement generally used to describe the capacity of a cell or battery.The product of discharge current(in Amperes )x the time of discharge(in hours),it is also used to describe the amount of electrical energy put back into battery during the charging process Abbreviated as A.H.or Amp.Hrs.
Active Materials
The material in the electrodes that takes part in the charging and discharging reactions.In the nickel-cadmium cell,nickel hydroxide and cadmium hydroxide are used as active mass at the positive and negative electrodes.In the lead cell,lead dioxide and sponge lead serve as the active mass at the positive and negative electrodes.The sulfuric acid in the lead cell which functions as an electrolyte can also be considered as an active mass,because it also takes part in the cell reaction.
Average voltage during discharge(Um)
Barium sulfate
An inorganic additive for negative lead masses(BaSO4).
Barton oxide
Lead oxide for active lead masses which is produced by means of a thermal process(Barton reactor) using liquid lead and atmospheric oxygen.
Barton reactor
See Barton oxide.
Battery Charge
Unit supplying electrical energy to a secondary battery.
Battery Test
This term describes the test for determining the charging condition and electrolyte level of lead batteries with liquid electrolyte.The charging condition is determined by measuring of the acid density.
Battery
One of the sources of direct current(D.C)power;a device that converts stored chemical energy directly into electrical energy(electricity ).Strictly speaking,a battery consists of two or more cells connected to form one unit,Through common usage,the terms “battery” and “cell” are now used interchangeably so that a battery I may refer to one or more cells.
Battery Case
Battery box containing the plate blocks,the connectors and the electrolyte.
Battery,Backup voltage storage
An accumulator which is constantly connected to a constant voltage source in order to maintain the capacity.
Battery Automotive
An accumulator which has been designed specifically for starting combustion engines.
Battery,filled and charged
Ready to use,charged lead battery filled with electrolyte.
Battery,maintenance
Battery that need not be refilled with water under normal circumstances.This term is often used for closed VRLA(valve regulated lead acid)batteries(electrolyte fixed by gel/glass mat).Product release.See Maintenance-free battery with fixed electrolyte.
Battery,rechargeable
See Secondary battery.
Battery,traction
An accumulator constructed for driving industrial electric vehicles.
Battery,unfilled and charged
Dry pre-charged lead battery which is activated by filling it with sulfuric acid of density=1,28 g/cm3.
Brushing
A method used to remove surplus paste from frames,lugs and the supports of a pasted plate.
Buffer Battery
An accumulator connected to a direct current source in order to reduce the voltage and current strength fluctuations.
Buffer charging
Charging method for emergency power batteries which uses a very small amount of charging current.The emergency power battery is continuously charged to compensate for possible losses in capacity.The battery is charged to 100% during the entire period of operation.
C
Rated capacity of the cell or battery.The charging and discharging current of a cell is often expressed as a multiple of C.(Example:The 0.1 C current for a cell with a rated capacity of 1.4 Ah is 140mA).See Capacity.
Cadmium
Chemical element(Cd)that belongs to the heavy metals.In battery technology,cadmium,cadmium oxides and cadmium hydroxide are used in the cadmium electrodes found in nickel-cadmium accumulators and in normal elements.
Cadmium electrode
A third electrode which functions as a reference electrode and is used for determining the potential of the positive/negative electrodes in lead cells.
Capacity
The available quantity of electricity of a battery or cell measured in ampere hours.The capacity is dependent on the battery temperature and the discharging current.It is therefore important to state not just the capacity,but also the discharging current and temperature(e.g. cold-start capacity in seconds with cold-test current and -18 celsius).
Capacity Loss,Permanent
A decrease in cell capacity in comparison to the level when it was new which cannot be restored by reconditioning.See Failure.
Capacity Loss,temporary S
A decrease in cell capacity that can be made good by reconditioning the cell. See Failure.
Capacity reconditioning
See Reconditioning.
Capacity,rated
The capacity that is typically delivered when used under normal conditions(e.g. 20-hour capacity in Ah,reserve capacity during discharge with 25 A in min).
Capacity,recoverable
See Capacity loss,temporary.
Capacity,residual
The capacity that can be drawn from a battery with an unspecified charge state(e.g. after a long period of non-use)when discharging with nominal current.
Casting
Production of a battery component(e.g. grid) by pouring a liquid lead alloy into a casting mold.
Cathode
The negative electrode at which reduction processes take place in a liquid solution,i.e. where cations(positively charged ions)are precipitated(gain in electrons).In secondary cells,each of the electrodes can become cathodes depending on the direction of the current.The positive electrode is the cathode when discharging.
Cell
The smallest unit of a battery, consisting of a positive and a negative electrode,a separator and the electrolyte.It stores electrical energy and forms the fundamental cornerstone of a battery if it is placed into a case and equipped with electrical connectors.The capacity of a cell is determined by its size.The cell voltage,however,depends on the electrochemical system of the element. See Element,electrochemical.
Cell case
See Container.
Cell receptacle
See Container.
Cell reversal
Cell polarity reversal is the reversal of the polarity of the individual cells in a single battery as a result of capacity exhaustion.Generally results in permanent battery damage.
Cell temperature,influence
Must not exceed the limits specified for operation(system-dependent)(e.g. at -30 celsius,battery acid with a density of =1.28 g/cm3 begins to freeze out[value determined from experiments on battery acid;the freezing point is far lower in the case of pure sulfuric acid];temperatures above 55 celsius increase wear and accelerate aging).
Cell,leak-free
See AGM,see Gel,see Maintenance-free battery with fixed electrolyte.
Cell,secondary
Rechargeable cell (e.g. lead,Ni-Cd,Ni-MH,Li-Ion)
Cell,starved
Cell which has suffered a reversible drop in capacity due to insufficient charging.
Cell gas outlet
A device for centrally drawing off gases formed in the battery via a gas duct(flue)in the battery cover.
Cell acceptance S
Describes the quantity of current in ampere hours which a battery in a defined charge state can accept at a specified temperature and charge voltage within a defined period.Often,the charging current(in amperes) flowing after this period has finished is measured instead(e.g. lead batteries: charge state 50%,charging voltage:14.4 V,temperature:0 celsius,duration:10 min,required current after 10 min:I10min>4×0.05 C20).The latter case is also known as”current acceptance”.
Charge efficiency
See Efficiency,Faraday.
Charge state
Remaining capacity(in %)referred to the rated capacity.
Charging
Feeding electrical energy into a battery.
Charging current
The current flowing at the time a battery is being charged.It depends on the charge state,the charging method and the temperature.
Charging factor
Ratio between the charged energy and the energy discharged earlier(in the case of a lead accumulator,lies between 1.05 and 1.20 depending on the model).
Charging voltage,maximum permissible
Charging voltage at which parasitic cell reactions occur(e.g. hydrogen generation).It must not be exceeded for longer periods of time.
Charging with charging current control
See Charging,IU characteristic.
Charging/characteristic
Charging with constant current without voltage monitoring.This is only expedient for small charging currents(e.g. I20),since otherwise parasitic reactions(increased temperature,water loss)can occur.
Charging,IU characteristic S
Charging is performed with a constant current until a gassing voltage is attained.Switchover is then made to U characteristic,the cutoff voltage lying below the gassing voltage.This results in the current dropping so sharply that the battery cannot be overcharged.
Charging,U characteristic
Charging with constant (cutoff) voltage.When the cutoff voltage is reached(e.g. 2.4 V per cell for a lead accumulator),the current is reduced automatically.
Charging,Wa characteristic S
As charging with *ka*W characteristic*ke* but with timed shutdown after a cutoff voltage is reached.
Charging,W characteristic
Charging using a resistance characteristic;the charging current drops as the charging voltage rises. When cheap chargers are used,gas forms and water is lost during recharge operations.
Cold Cranking
Cold cranking is the discharge current given by the manufacturer.It is emitted by a battery at a temperature of -18 celsius with a minimum voltage of Ui=7,5 volt for a period of 10 seconds,according to the EN specifications.
Conditioning
The cyclical charging and discharging of a battery to ensure that it is fully charged when supplied. Conditioning isalso known as ‘putting into service’ when batteries have fixed electrolyte.
Connecting cable
A flexible cable for establishing an electrical connection between the battery and the consumer or battery charger.
Connecting strap
See Connector.
Connector
Component connecting the terminals of a cell.Is usually a cast component.See COS.
Conservation charging
Charging method in which the battery is maintained in a fully charged condition and is therefore always ready for use(e.g. as an emergency power supply).
Constant current charging
Constant current charging involves charging with a constant charging current and variable charging voltage.
Constant voltage charging
A charging procedure in which the applied voltage hardly changes regardless of the battery charge state.It is the most frequently used method for closed lead batteries.
Container
See Battery Case.
Corrosion
The gradual oxidation of the metallic lead to lead dioxide in the grid of the positive plate.
COS
Cast On Strap.Abbreviation of the designation for the manufacturing process used for the plate block which involves connecting the plate lugs of several like electrodes(parallel connection to increase the capacity) in a connecting strap made of lead alloy.
Cover
A component for closing a battery case.
Curing
Chemical process applied to the grid plates of lead batteries following pasting.There are essentially 3 stages:
1.Oxidization of residual lead to PbO
2.Formation of the grid/mass transitional structure
3.Drying of the plate Conversion from tribase to tetrabase lead sulfate is also possible depending on the temperature profile used for the curing process.
Current
The movement of electrical charges in an electrical field.Battery technology only uses direct current.
Current collector
A structure within the electrode that makes the flow of current between the cell terminals and the active mass possible. See Grid.
Current strength
Current strength,when used for charging or discharging,is often expressed as a fraction or a multiple of the specified current strength C.
Cutoff voltage
The voltage at an accumulator’s terminals just prior to the interruption of the charging current.
Cutoff ,voltage and temperature dependent (VTCO)
A way of switching the charging current of a battery from highest-speed charging to peak charging by means of a control circuit in the battery charger.This circuit is activated by the battery voltage or battery temperature.
Cycle
Charging followed by discharging,usually repeated at regular intervals.
Cycle stability
The cycle stability of an accumulator is a measure of how often it can be charged and discharged. Cycle strength is particularly important in the case of solar batteries,as they are charged during the day and discharged at night.
Cycle service life
See Service life,cyclical.
Can Liner
Sheets of non-conductive,electrolyte resistant materials that are inserted between the cells and battery can to provide insulation.(Note:Most Marathon batteries haven epoxy coating which is applied to the can by a fluidized¨Cbed process,These do not require liners)
Carbonyl-Nickel Powder
1A special type of pure nickel powder that lends itself to preparing highly porous and mechanically strong plaques used in the manufacture of the plates of sintered plate nickel cadmium batteries.
Cell Puller
A specially designed too [used to facilitate the removal of cells from a battery.
Cell Support
A plastic barrier that is placed in the cell above the plate core to strengthen the cell case against possible collapse,It also serves to protect the edges of the plates from objects,falling into the vent hole and is sometimes used as an electrolyte level reference.
Charge Efficiency
Charge efficiency indicates the ease with which a battery can be charged. It is obtained by dividing the discharge capacity by the product of the charging current and the time.Usually expressed as a percentage.
Charge Retention
The amount of capacity retained(or deliverable)by a fully charged battery after it has been stored for a stated period of time.Sometimes called shelf life.
Closed Circuit Voltage
The instantaneous voltage of a cell or battery when a load is first applied.
Deep discharge
State in which a cell is fully discharged using low current,so that the voltage falls below the final discharging voltage.
Degassing
Release of charge gases from the cell openings provided(plug,valve,gas duct).
Density,nominal(specific weight of the electrolyte)
The nominal density of the electrolyte is a value specified by the manufacturer for a nominal temperature and normal electrolyte filling level in the cell.
Diffusion
Driving force for compensating differences in concentration in the electrolyte.
Direct current
Current, whose polarity does not change over time (e.g. current from an electrochemical power source).
Discharging
Sometimes called constant voltage charging this refers to a method in which a fixed voltage source is applied across the battery terminals, The charge current is variable and depends primarily upon the difference in voltage between the voltage source and that of the battery, The initial charge current is high and decreases as the battery accepts the battery accepts the charge and its voltage, increases.
Discharge depth
The capacity drawn from a battery divided by the rated battery capacity and expressed as a percentage(e.g. 50% discharge depth for a battery with a rated capacity of 50 Ah means that a capacity of 25 Ah is drawn).
Discharging current
Drawing current strength of a battery. It can be expressed in absolute(in amperes)or relative terms (as a fraction or multiple of the C current strength).
Discharging voltage, average
The average discharging voltage is the average value of the discharging voltage during the entire discharging process with a related discharging current.
Element, electrochemical
Combination of anode and cathode materials for creating an electrochemical cell (e.g. manganese dioxide / zinc, PbO2/Pb, Ni/Cd).
Emergency power supply
Class of battery applications where the battery is used as a power source when the AC supply from an electrical power company fails.
Endurance test
The performance of an accumulator, which undergoes electrical or physical continuous load testing in the lab. Included are such tests as charging anddischarging or overcharging of batteries or cells.
Energy
Energy expressed in watt hours, which under specific conditions can be released from the battery during discharging. See Working capacity.
Energy density
The stored energy in a battery or a cell. It is related either to mass (gravimetrical energy density in watt hours per gram) or to volume (volumetric energy density in watt hours per cubic centimeter).
Equalizing charge
An equalizing charge is an extended charge (up to 20% overcharge) for guaranteeing a fully-charged state.
Equivalent circuit
Circuit diagram which uses ohmic electrical symbols to illustrate the electrical behavior of an electrochemical store.
Eutetic(system)
The point in the state diagram of an alloy consisting of several fully mixable alloy components at which the alloy has the lowest possible melting point(e.g. Euteticsystem of a lead-antimony alloy: Pb:Sb=88.9:11.1 with melting temperature TEutetic=252 celisus.)
Expander
An additive consisting of organic and/or inorganic components (lignin, lamp black, barium sulfate) for negative mass. The expander is used to delay shrinkage of the sponge lead when the battery is in use.
Failure
A state in which a battery no longer functions satisfactorily. There are several forms of failure.
Failure,permanent
A state in which a cell or battery cannot be recharged to a satisfactory level.
Failure,reversible
A failure condition that can be remedied by using particular electrical procedures or by reconditioning.
Final charging current
The final charging current is the current at the end of an IU charging operation (gassing current).
Final discharging voltage
Indicates the lowest allowable voltage level that a battery or cell can be discharged to. Discharging to below this cutoff voltage (deep discharge) can impair or (throughpole reversal) destroy the electrochemical cell in the case of various battery types(e.g. lead, Ni-Cd, Ni-MH).
Forming
Initial electrical charging for converting the active masses into the charged state (e.g. PbSO4 -> Pb (-) und PbO2 (+) )
Frame
The reinforced outer parts of a battery grid.
Fully-formed
Batteries, particularly closed lead batteries, in which the paste on the plates has been totally converted to active mass. See Conditioning.
Galvanic element
Current source whose electrical energy is released through electrochemical processes.
Gas formation(gassing)
The development of hydrogen and oxygen when overcharging electrochemical cells with hydrous electrolytes.
Gas outlet,central
See Central gas outlet.
Gel
Electrolyte jellified through the addition of silicic acid to sulfuric acid.
Gel battery
See Maintenance-free battery with fixed electrolyte.
Grid growth
Deformation of the frame of positive grid plates resulting from corrosion of the grid lead.
Grid
A frame that supports the active mass in an electrochemical cell.
Grid plate
A grid in an electrochemical cell which is pasted with active mass.
Heavy duty
Battery type with an above-standard cycle stability and shock resistance. Applications: Commercial vehicles, construction and farm machinery.
High current charging
Charging with a current strength greater than 1C.
High current discharging
Discharging with a current strength greater than 5C.
I.E.C
International Electrochemical Commission.
Impedance
Apparent resistance of an alternating circuit to current; comprised of reactance and ohmic resistance. See Resistance.
Industrial battery
A storage battery which is used to supply power to industrial equipment (e.g. fork-lift trucks).
Initial charge
The initial charge is the first charging process after the electrolyte has been poured into a dry precharged battery.It has the purpose of bringing the cell or battery to fullinitial capacity.
Initial temperature
The temperature of the electrolyte in an accumulator when discharging or charging begins.
Initial voltage
A battery’s initial voltage is the working voltage when discharging begins. Measurement usually follows, as soon as current has flowed long enough for the voltage to remain at a constant level, for example after 10% usage of a previously fully-charged cell.
Inner resistance
Ohmic resistance of a battery.
Inner resistance,effective
The measurable resistance against the flow of current in a battery expressed as a drop in the battery voltage proportional to the discharging current. The value isdependent on the manner of construction, the charge state, temperature and the age of the battery.
Insulation resistance
Insulation resistance is the resistance between a cell or battery and a mass/earth (motor-vehicle body, torso).
Lamp black
A fine carbon powder used as an ingredient for negative lead masses. Component share <0.5%.
Lead(Pb)
A chemical element which belongs to the heavy metals (specific weight 11.341 g/cm3). It is used in the form of bivalent and / or quadrivalent compounds (PbSO4 or PbO2), as porous sponge lead for active masses, and as lead-antimony or lead-calcium alloys for grids in lead batteries.
Lead battery
An accumulator in which the electrodes consist primarily of lead, whereas the electrolyte consists of diluted sulfuric acid. Product release: Automotive BatteriesCatalog.
Lead dioxide
Quadrivalent lead oxide (PbO2), which is generated electrochemically during formation and which forms the active mass of the positive lead electrode. Color: black-brown.
Lead oxide(Litharge)
A bivalent lead oxide (PbO), which can occur in two modifications: the orthorhombic, yellow high-temperature modification and the tetragonal, red modification. It is used in producing active lead masses.
Lead sulfate(PbSO4)
Chemical compound produced on the positive and negative plates of a lead battery during discharge. It is the result of a chemical reaction between the sulfuric acid and lead dioxide of the positive electrode or the metallic lead of the negative electrode.
Lead sulfate,tetrabase
Chemical formula 3 PbO·PbSO4O. This is formed during mixing of the active mass from lead oxide + acid + water at temperatures below 60 celsius and consists of flake-shaped crystallites of approx. 1 micro meter diameter.
Lead,free(Pb metallic)
Non-oxidized residual lead in cured lead plates. See Curing.
Lead-cacium alloy
A lead alloy for grids used in maintenance-free lead batteries. The typical calcium component is approx. 0.08%.
Lead-coated part
A metal part with a thin protective coat of metallic lead that has been deposited on the surface by galvanization.
Lignin
General term for the non-cellulose wood component (lignin sulfuric acid or desulfonate sulfuric acid). It is the main component of the additives for negative leadmasses with a component share of <1%. It is sold under the name Vanisperse.
Load
Describes the current in amperes with which a fully charged battery can be loaded over a defined period and at a defined temperature without the voltage falling below a pre-specified cutoff voltage.
Loss
See Fading.
Low current charging
Charging with a current strength that is only slightly higher than what is needed to compensate for self-discharge losses.
Low current discharging
Discharging with current flow under 0.1 C.
Machine casting
A full or semi-automatic casting process for grids or small parts.
Maintained capacity
The battery is kept in a fully charged state by means of a constant voltage charger with a low charging voltage (compensates for self-discharging).
Maintenance-free battery
See Battery, maintenance-free; see Maintenance-free battery with fixed electrolyte.
Maintenance-free battery with fixed electrolyte
Lead-acid battery in which the electrolyte is held in place in a gel or microglass mat (AGM). The battery is sealed and is equipped with valves. It is highly stable and exhibits good cycling characteristics.
Mass,active
The material in the electrodes that takes part in the charging and discharging reactions. In the nickel-cadmium cell, nickel hydroxide and cadmium hydroxide areused as active mass at the positive and negative electrodes. In the lead cell, leaddioxide and sponge lead serve as the active mass at the positive and negativeelectrodes. The sulfuric acid in the lead cell which functions as an electrolyte can also be considered as an active mass, because it also takes part in the cell reaction.
Maturing
See Curing.
Mold,casting
A component made of cast iron or steel in which the required geometry of the mold takes the form of a cavity (e.g. casting mold for producing lead grids).
Monoblock battery
Multi-cell battery in a block box. See Battery case.
Negative electrode
See Electrode, negative.
Negative terminal
Negative pole of a battery.
Nominal voltage
See Voltage, Nom.
OCV
Abbreviation for Open Circuit Voltage.
Open circuit voltage
The open circuit voltage is the voltage of an accumulator which is without external consumers (not under load). It is generally higher than the nominal voltage.
Operating voltage
See Working voltage.
Over-discharge
See Deep discharge.
Overcharging
Charging beyond the fully loaded stage. This can result in battery damage (loss of electrolyte).
Overcharging current
Current which flows in the fully charged battery when the gassing voltage is applied (e.g. 2.4 V per cell at 25°C for the lead battery). It results in capacity maintenance and water loss.
Oxidation
Release of electrons through the cell’s active mass to the external electric circuit. During the discharging process, cadmium is oxidized at the negative electrode of the nickel-cadmium cell or sponge lead is oxidized at the negative electrode of the lead cell.
Oxide(of lead)
See Lead oxide.
Oxy-hydrogen gas
Gaseous mixture of hydrogen and oxygen (H2O2 mix) which is extremely flammable over a wide composition range. Oxy-hydrogen gas is created when overcharging battery systems with hydrous electrolyte.
Oxygen evolution
Gaseous oxygen is reduced from the electrolysis of water when a battery at the charging stage reaches a certain voltage. See Gas formation.
Oxygen recombination
Electrochemical process in which oxygen is produced at the negative electrode with the formation of water. See Maintenance-free battery with fixed electrolyte.
Parallel connection
Connecting all the positive or all the negative poles of several batteries. This increases the capacity of a battery network while maintaining a constant voltage.
Part,lead-coated
See Lead-coated part.
Paste
Mixtures of various compounds, (e.g. lead oxide and water, sulfuric acid) that are used to coat positive and negative lead battery grids. A distinction is made between positive and negative pastes depending on the recipe. These pastes are then transformed into positive and negative cured masses. See Mass, active; see Curing.
Paste consistency
A term that includes the physical characteristics of the paste, such as density and elasticity.
Pasting
Application of active pastes to lead grids.
Pickling
Immersing a positive lead plate into a diluted sulfuric acid solution. A process in which specific plate types are saturated in sulfuric acid after pasting. The saturation produces a protective surface and a supply of sulfate which supportscontainer and tank formation.
Plate
An electrode consisting of active mass and conductive carrier.
Plate block
Assembly of alternating positive and negative plates. In order to electrically isolate the plates from each other, one plate sort (positive or negative) is fitted with a pocket separator.
Plate,negative
See Electrode,negative.
Plate,positive
See Electrode,positive.
Plateau
See Voltage plateau.
Plug
Component with venting ducts for sealing a cell opening.
Polarity
Electrical term for describing the charge or voltage relationship between two electrodes.
Pole
See Terminal.
Pole reversal
See Cell reversal.
Pores
Cavities in an active battery mass.
Positive electrode
See Electrode, positive.
Positive plate
See Electrode, positive.
Positive terminal
Positive pole on a cell or battery.
Power,electromotive
See Electromotive power.
Pressure die casting
Method for producing lead grids where liquid lead is pressed into a casting mold under high pressure.
Purified water
Distilled or demineralized water for compensating the water losses in batteries requiring maintenance.
Rated capacity
The capacity in Ah (as defined by the manufacturer) under defined discharging conditions (current, temperature).
Reaction,reversible
Chemical reaction that can take place in either direction (oxidation or reduction). The cell reaction must be reversible in order to use a secondary battery (e.g. charging or discharging a secondary battery).
Rechargeable battery
See Secondary battery.
Recharging
Creating a fully-charged state from any charged state (e.g. caused by self-discharging).
Reconditioning
Discharging with low current (e.g. I100) and recharging with approx. 30% overcharge. The procedure can be repeated if required.
Recoverable capacity
See Capacity loss, temporary.
Red lead(Pb3O4)
Lead compound produced from bivalent and quadrivalent lead oxides. Is used as a forming aid for positive lead masses.
Reduction
Increase in the number of electrons. In the case of a cell, this term refers to the electron transfer to the active mass. During the discharging operation, NiOOH(charged positive mass of nickel-cadmium or Ni-MH accumulators) or lead dioxideat the positive plate is reduced to a lower oxidation state (to Ni(OH)2 or PbSO4).
Remaining capacity
The capacity that remains after discharging.
Remaining charge
Full charge from undefined charge state.
Resistance, inner
See Inner resistance.
Reversal
See Cell reversal.
Reversible failure
See Failure, reversible.
Reversible reaction
See Reaction, reversible.
Round cell
Round cell, in contrast to prismatic cell.
Safety ventilation
A recloseable ventilation that reduces abnormal gas pressures arising from misuse.
Sealing compound(filler)
Material used to seal the terminals opening in the cell cover.
Sealing plug
See Plug.
Secondary battery
Rechargeable battery. See Accumulator.
Secondary cell
See Cell, secondary.
Self-discharging
Self-discharging is a temperature-dependent permanent chemical reaction process at a cell’s or battery’s electrodes, without connection to a consumer.
Separation
A separator is fitted between the positive and negative electrodes in order to isolate the latter from each other electrically.
Separator
A device used for the physical separation and electrical isolation of electrodes of opposing polarities. In certain cases, the separator can also be used for absorbing superfluous electrolyte (micro glass mat AGM). The separator for acid electrolytes generally consists of a porous PP/PE foil, while the separator for alkaline systems generally consists of PP/PE mats.
Seres connection
Connection of the positive terminal of a cell / battery to the negative terminal of the next cell / battery. This increases the voltage of the battery network while keeping the capacity constant.
Service life
The length of satisfactory performance measured in years or charging / discharging cycles.
Service life,cyclical
The number of cycles a battery lasts before its capacity falls below the acceptable value.
Service life,useful
The useful service life of an accumulator expressed as the period of time prior to its capacity falling to a specified component of the rated value.
Service,putting into
See Conditioning.
Shock-resistant
Battery protection against vibration achieved through design measures (e.g. fixing a plate block in position using hot-melt adhesive).
Short circuit,inner
The cells can also experience an inner short circuit in the case of fine short circuits (see Tree formation). This will generally result in high self-discharging and will bereflected in a sharp reduction in capacity.
Short circuit,outer
Low-impedance electrical contact between the battery poles. High temperatures can result in the battery being destroyed.
Shrink holes
Casting defects, i.e. holes, hollows or depressions in the castings.
Sinter plate
An alkaline accumulator plate, whose support is formed from sintered metallic powder and which contains the active mass.
Slag
The layer of various oxides and impurities which form on the surface of molten metal.
Sludge
Waste from battery paste during pasting. Exhausted positive mass during the aging process.See Sludging.
Sludging
Chemical process that takes place during discharging and charging onto the positive plates and results in the irreversible loss of positive mass.
Sponge lead
Lead which is deposited electrochemically on the negative electrode; it has a sponge-like structure with high inner surface.
Stacking
Procedure during cell mounting in which plates and separators are stacked alternately in a box before the connecting strap is cast. See Connecting strap. See COS.
Standard capacity
See Capacity, nom.
Standard charging
Charging current that can be maintained indefinitely without the need for special cells or switchable battery chargers. Under normal circumstances, cells can be charged overnight in 12 to 14 hours.
Starved cell
See Cell, starved.
Stibine(antimony hydride SbH3)
Gaseous compound that forms on negative plates of lead-antimony cells, particularly when charging quickly or overcharging excessively.
Storage battery
See Secondary battery.
Sulfatation
The formation of lead sulfate at the electrodes of a lead accumulator by recrystallization when the battery remains unused for a long time in deep discharge state. A coarse grained lead sulfate is produced which can only be recharged with difficulty. See Reconditioning.
Switchback,temperature-dependent
Method for switching the charging current of a battery from highest-speed charging current to conservation charging current by means of a control circuit in the chargerwhich is triggered by the battery temperature.
Tnom
See Temperature, nominal (Tnom).
Tapered battery charger
A simple, economical battery charger that delivers high charging currents to discharged batteries, then gradually reduces the current as the battery voltageincreases and nears its fully-charged state. Not suitable for closed nickel-cadmiumbatteries and some other applications due to the occurrence of AC voltage fluctuations. See Charge, W characteristic.
Temperature,nominal(Tnom)
An electrolyte’s nominal temperature is a specified value which is used as a reference value for capacity tests (e.g. according to European standard EN 60095-1Tnom lies in the region of 23-27 celsius for the 20-hour capacity of lead batteries).
Terminal
Polarity-specific component on the battery for making a (detachable) connection with the consumer.
Thermal instability
See Thermal runaway.
Thermal runaway
Continuous heating of the electrolyte up to the boiling point due to an increase in charging current as the charging voltage decreases (lead accumulator with falling charge characteristic).
Tinning
Coating a metal surface with tin, either with tin enamel (fine tinning) or tin alloy (galvanic).
Tracton battery
See Battery, traction.
Tree formation
Describes the growth of a lead dendrite, in the case of a lead discharge, through a hole, a crack, or a large pore of a separator, such that the cell becomes short-circuited.
Valve
A device allowing gas to escape when inner pressure is too high, while preventing air from entering.
Venting valve,recloseable
Safety valve in the cell which opens in case of overpressure and closes again automatically when normal pressure has been restored (e.g. gel battery, AGM battery).
Volt
Unit of measurement for electrical voltage. Abbreviation V. Named after the Italian physicist and doctor Count Alessandro Volta (1745 – 1827).
Voltage and temperature dependent cutoff(VTCO)
See Cutoff, voltage and temperature dependent.
Voltage dip
A momentary drop in voltage when high current discharging is used (e.g. in the case of lead accumulators).
Volatge drop
Should current flow through a resistor inside a closed electric circuit, a voltage drop will occur.
Voltage plateau
A slow decrease in voltage over a long period of time. Characteristic for many discharges of closed cadmium cells and closed lead cells. As a rule, the plateau extends from the first voltage drop at the start of the discharge to the bend of the curve after which the voltage drops rapidly at the end.
Voltage,nominal
The battery’s average voltage during discharging with a low current strength.The manufacturer specifies the value on the accumulator(e.g. Ni/Cd=1.2 V per cell).
Water,purified
See Purified water.
Welding
Connecting together two or more plates to form a plate block by welding on a connecting strap.See COS.
Working capacity(energy)
The working capacity of a cell or battery is the dischargeable electrical energy in watt hours[Wh] for an accumulator with average discharge voltage and corrected to Tnom.See Energy;See Temperature,nominal(Tnom).
Working voltage
The working voltage of a cell or battery begins at its electrical connections as soon as an electrical consumer is connected to it;it is smaller than the nominal voltage.