acid battery Lead- y - kind of an electric battery based on galvanic cells made of lead electrode, the electrode of lead oxide (IV) (PbO2) and approximately 37% sulfuric acid aqueous solution, fulfilling the role of the electrolyte.
lead battery was invented by French physicist Gaston Plant in 1859 Despite its many flaws it is still the most popular type of electric accumulators. It occurs in almost all new cars, as well as many other vehicles (eg Melex). In addition to this is often one of the elements of an emergency supply of buildings, industrial plants, hospitals, telephone exchanges and field lighting systems.
Car battery 12V/40Ah
typical car battery is built with 6-cell lead-acid batteries connected in series. Each cell generates an electromotive force (SEM) was equal to 2.1 V. All the battery generates a voltage rating equal to, therefore, 12.6 V battery internal resistance is very low, enabling the transfer of very large currents. For this reason, were used as starter batteries for internal combustion engines.
single cell consists of:
In this cell, during current consumption of the following chemical reactions occur at the electrodes: the anode
- oxidation
As can be seen on both electrodes while the current of isolated sulfate (VI), lead (II) (PbSO4). While charging, there are exactly the same reactions, so that the other way.
charged battery in the gravity of the electrolyte is 1.26 - 1.28 g/cm3 (in batteries for use in tropical climates 1.23 g/cm3). The process reduces the discharge of the electrolyte concentration and density. When the battery is running low voltage at the poles will fall to 1.8 V and the density of the electrolyte to 1.18 g/cm3, the battery must be recharged immediately. The charge state can be measured hydrometer.
status of battery consists of a total transformation of the two electrodes in a solid lead sulfate and is irreversible. Sulfate lead after some time passes in the crystalline state, which is an electric insulator, it is hard reacting, resulting in decrease in battery capacity. In practice, the so-called avoided. zasiarczeniu electrodes using a special their design, which impedes the deposition on the surface of impermeable layer of lead sulfate crystals. Car batteries are not generally designed to be frequently fully discharged, but rather to function in a position to fully charge.
lead battery was invented by French physicist Gaston Plant in 1859 Despite its many flaws it is still the most popular type of electric accumulators. It occurs in almost all new cars, as well as many other vehicles (eg Melex). In addition to this is often one of the elements of an emergency supply of buildings, industrial plants, hospitals, telephone exchanges and field lighting systems.
Construction and operation of
single cell consists of:
- anode made of lead metal - (-) - During the current consumption and (+) during charging
- cathode made of PbO2 - (+) - During the current consumption and (-) during the charging
- electrolyte - which is an aqueous, approximately 37% sulfuric acid solution with various additives
Unloading
In this cell, during current consumption of the following chemical reactions occur at the electrodes: the anode - oxidation
As can be seen on both electrodes while the current of isolated sulfate (VI), lead (II) (PbSO4). While charging, there are exactly the same reactions, so that the other way.
charged battery in the gravity of the electrolyte is 1.26 - 1.28 g/cm3 (in batteries for use in tropical climates 1.23 g/cm3). The process reduces the discharge of the electrolyte concentration and density. When the battery is running low voltage at the poles will fall to 1.8 V and the density of the electrolyte to 1.18 g/cm3, the battery must be recharged immediately. The charge state can be measured hydrometer.
status of battery consists of a total transformation of the two electrodes in a solid lead sulfate and is irreversible. Sulfate lead after some time passes in the crystalline state, which is an electric insulator, it is hard reacting, resulting in decrease in battery capacity. In practice, the so-called avoided. zasiarczeniu electrodes using a special their design, which impedes the deposition on the surface of impermeable layer of lead sulfate crystals. Car batteries are not generally designed to be frequently fully discharged, but rather to function in a position to fully charge.
Charge Charging the battery is connected to the power source (Eg power supply or battery charger) and it lasts about 10 hours. The charging current is 10% capacity (40 Ah for the battery charging current is 4 A). It is possible to load the accelerated (1 hour) according to manufacturer's recommendations. When charging the cell voltage rises slowly from about 2 V to 2.35 V, then faster. The density of the electrolyte increases. After crossing the 2.4 V starts with the distribution of water into oxygen and hydrogen (the gassing of the battery). After reaching 2.5 V voltage charging should be stopped, otherwise it comes to overloading the battery. This results in the separation of large quantities of hydrogen (called boiling). Hydrogen in combination with air form an explosive mixture which can explode if a spark of electricity. Hence, charging should be carried out in well-ventilated indoors or in the open air and to avoid arcing when disconnecting the charger terminals (unplug the charger from the network). During the loading emits heat in the electrolyte, which at a temperature above 40 ° C of damaging the battery plates. You should not use the batteries sold in Poland at an ambient temperature above 40 ° C.
Unused battery must be periodically (Monthly) recharged to prevent sulphation caused by self-discharging of the battery.
Capacity Lead Acid Battery Capacity is given in ampere hours (Ah). Capacity depends on how the discharge, which is why the concept of a 10-hour capacity. For example, to unload within 10 hours of battery 40 Ah, you should reap the A current of 4 A. In freezing temperatures
Capacity decreases causing difficulties in getting vehicles in winter. At high frost fully discharged battery may be to freeze the electrolyte, leading to its failure. In the old days was recommended removing the battery from the car, store in a warm place and fit before starting the engine. Currently, work on the batteries in modern cars are often prohibited because of possible damage to the electronics and erase the memory controllers.
batteries so. "Maintenance free" and "gel"
disadvantage is the risk of lead-acid batteries have leaked sulfuric acid and water evaporation resulting in too much of its concentration in the electrolyte and the need to periodically be replenished. Both problems are solved using either very tight, nierozbieralne housing or using gel electrolytes. Gel electrolytes are still aqueous solutions of sulfuric acid, but added to them gelling agent (eg, silicone resins), which also prevents water evaporation and leakage. Both types of batteries - sealed and the gel is called "maintenance free" - because basically they do not require checking the composition and amount of electrolyte.No form of electrolyte, however, does not prevent problems arising from the frequent discharge of the battery. Charging the battery "maintenance free" is performed in the same way as the "maintenance" Do not just make them self-filling electrolyte.
battery housings are never absolutely tight, because this would constitute a danger of explosion due to the large increase in pressure in the interior as a result of the evolution of hydrogen during its handling.
battery in the numbers
typical car battery (battery start - ed.), Composed of six cells holds:- electromotive force V = 12.6
- minimum voltage (indicating a state of deep discharge ) - 11.8 V
- Proper charging voltage - minimum: 13.9 V - 14.5 V maximum voltage overload
- - occurring during the evolution of hydrogen> 14.7 V
- In the case of intentional discharge of the battery is charging it with a low constant current to voltage even 16.5 V
Sample parameters
| Battery Type | number of cycles | Volume (1 kWh) | Mass (1 kWh ) | Price (1 kWh) |
| Pb * | 1 500 | 12 dm ³ | 24 kg | $ 80 |
Article taken from Wikipedia:
http://pl.wikipedia.org/wiki/Akumulator_kwasowo-ołowiowy
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