V40 L4-1.9L Turbo VIN 29 B4204T3 (2002)
iron. The iron breaks down and corrodes. The battery terminal is vulnerable to corrosion if it is not maintained correctly.
Short-circuit
A short-circuit is when the current takes a short cut where the resistance is less and therefore does not go via the intended route. A short-circuit can be
caused for example by particles detaching from the plates in the cells. Eventually these deposits can be so large that a conductive connection is made
between the two plates so that the current can flow between the two plates instead. A short-circuit in a cell can fully discharge a battery and render the
battery useless.
Cold cranking amperes
A measurement of the ability of the battery to start the car. The cold cranking amperage is expressed as a CCA value. Volvo batteries are usually marked
with a CCA value according to the SAE norm. The cold cranking amperes according to the SAE norm is defined as the current that a fully charged
battery can supply at a temperature of -17.8°C (0°F) for 30 seconds without the voltage dropping below 7.2 V. The higher the cold cranking amperes
value, the better the starting capacity of the battery. In certain markets the batteries are marked according to the DIN norm.
Charging
The process by which a battery is supplied with energy by a charger or the generator (GEN) in the car. During charging, the lead sulphate in the plates is
converted back to pure lead on the negative plates and to lead oxide on the positive plate. Water is consumed, sulfuric acid is formed and the density of
the acid increases.
This reaction can be written:
2 PbSO4 + 2 H2O -> PbO2 + Pb + 2 H2SO4
State of charge, SOC
The state of charge is expressed as the amount of electrical energy that is stored in the battery at any given time, in relation to how much energy can be
stored in a fully charged battery. The state of charge is listed as a percentage of full charge. This is the "State of Charge", SOC.
Direct current, DC
An electrical current that only travels in one direction in an electrical cable. A battery supplies direct current during discharge and must be recharged
(from the generator (GEN) or an external battery charger) with direct current in the opposite direction to current during discharge.
Plate
The plates in a battery function as electrodes. Each cells consists of several positive and negative plates. These plates are welded together in groups by
plate straps. The plate is made up of a grid with an external layer of active material. This active material contributes to the electrochemical process
during charging and discharging. The grid is constructed of a type of a lead alloy which functions as a conductor of the active material and also carries
the current. The positive plate has an external layer of lead dioxide, while the external layer on the negative plate consists of porous lead.
Plug (not maintenance-free as well as AGM-batteries)
On top of the battery is a cover with six plugs, one for each cell. The plugs can be opened when checking and topping up the electrolyte.
Reserve capacity, RC
The reserve capacity, RC, is measured in minutes and is, according to the SAE norm, the time taken to discharge a fully charged battery at 25 A to a
voltage of 10.5 V at a temperature of +25°C (+77°F). The reserve capacity is the length of time the battery is able to supply necessary components with
current when the generator (GEN) in the car is not functioning. Volvo batteries are marked with the RC value according to the SAE norm.
SAE
An industry norm. SAE is an abbreviation of "Society of Automotive Engineers".
Separator
See Separator.
Self-discharge
A battery that is not in use will discharge itself over time. This is know as self-discharge and is quicker in hot environments. The battery must be
maintained by recharging at regular intervals to avoid excessive discharge.
Sulfation
