Car Battery Problems
A car battery needs to be efficient to supply current to the different parts of the vehicle. It depends upon the two factors -
- Temperature.
- Rate of Discharge.
At low temperatures, the battery is less efficient and cannot supply for a long time, because chemical activities are greatly reduced and Sulphuric acid cannot work so actively on plates.
So car battery problems are always there to hamper the electricity of the vehicle. The main 8 problems are-
- Self Discharging.
- Sulphatation.
- Internal Short-Circuiting.
- Deterioration of Plates.
- Cracking of Container.
- Corrosion of Battery terminals and clamps.
- Loss of Water.
- Variations in Specific Gravity of Electrolyte.
Each and every problem are discussed below-
1. Self Discharging
If a battery is left standing for a few days, it is discharged by itself, the process is called self-discharging. New batteries usually get discharged at the rate of one percent per day of storage. The rapid self-discharging, 3% or more, is considered a serious defect of the battery.
Self-discharging of batteries takes place due to contained electrolytes, damaged separators, and long-term storage. Therefore, pure Sulphuric acid(not commercial) and distilled water(not tap water)should be used to prepare the electrolyte. Care must be taken while inspecting the battery, so that dust or dirt particles may not enter the battery.
Care must be taken while handling the battery. Battery plates or separators may not be damaged.
If a car is standing for a long period, it causes stratification of the electrolyte. The bottom layers become heavier than the top layers. In such a case local equalizing current sets up which increases the rate of self-discharging.
If a battery is self-discharging, it should be discharged to 1.2 volts per cell. This will transfer metallic impurities from negative plates to the electrolyte. Then the electrolyte is drained and the battery is washed thoroughly first with clean water and then with distilled water. Now, the fresh electrolyte is put in the battery and then it is recharged.
2. Sulphation
When a battery is discharged, the lead Sulphate forms and deposits on the plates. When it is being recharged, the Lead sulfate again converts into active materials- the lead peroxide and songy lead. However, if a battery is kept standing for a long time in a discharged condition, large lead Sulphate crystals, whitish in color, deposit on the plates, which do not convert back into the active materials of recharging. This condition is called Sulphation. The accumulation of these crystals increases the internal resistance of the cells and causes the plates to buckle or break.
The very high specific gravity of electrolytes and insufficient electrolyte are also the cause of Sulphation. Care should be taken so that sulphation may not take place. The Sulfate battery can, however, be recharged by keeping the charging rate low. It is advisable not to use heavily discharged batteries.
3. Internal Short-Circuiting
It takes place due to the damaged separators. It is also caused by the active material dropping from the plates which form a heap so high to make short-circuit. It results in rapid self-discharge and sulphation. To avoid internal short-circuiting, the damaged separators should be replaced and the battery should be cleaned.
4. Deterioration of Plates
The battery plates get deteriorated for the following reasons-
- Very high charging rate.
- The high specific gravity of the electrolyte.
- Freezing of electrolytes.
- Improper level of electrolyte.
- Mechanical damage due to rough handling or not fixed in the vehicle, The deteriorated plates should be replaced.
5. Cracking of Container
The battery container may crack due to rough handling or due to shocks on rough roads. If the cracks are on the interior walls, they cause the electrolyte to leak. The only remedy is to replace the cracked container.
6. Corrosion of Battery Terminals and Clamps
Corrosion usually occurs on the battery terminals and clamps due to oxidation. It breaks the circuit. Therefore, the battery terminals and clamps should be cleaner periodically.
7. Loss of Water
The electrolyte is a mixture of Sulphuric acid and water. The water gets evaporated slowly. It reduces the electrolyte and makes the electrolyte concentrated. Therefore, the electrolyte level in the battery should be checked periodically. Add distilled water, if required to make the electrolyte up to the correct level and its specific gravity to a proper value.
8. Cell Gravity Variation
The gravity of all the cells in a battery should not vary. It must be the same for all the cells. If the gravity reading of a cell is less than the other by more than two gravity points, it indicates the loss of acid from this particular cell.
These are the basic lead-acid car battery troubleshooting or the problems that happened in an automobile vehicle. So testing the battery all the time and keeping it healthy is important for the rider.
How to Test the Lead-Acid Car Battery
Battery testing is necessary to access the quality of the finished battery. It indicates whether the battery is capable of meeting the minimum performance requiring the vehicle's electrical system. A battery can be tested to ascertain its condition by the following tests-
- Specific Gravity Test.
- Open Volt Test.
- High Discharge Test.
- Cadmium Test.
1. Specific Gravity Test
Specific gravity test with the hydrometer. |
Reading. | Condition. |
---|---|
1.220-1.230 | Fully charged. |
1.200-1.210 | 3/4 charged. |
1.175-1.185 | Charged. |
1.150-1.160 | Charged. |
1.125-1.135 | Very little charged. |
1.100-1.110 | Discharged |
The specific gravity test should not be made while the battery is gassing. The test should also not be made immediately after the water has been added to adjust the electrolyte level, otherwise, this would affect the reading.
2. Open Volt Test
The open circuit voltage of a fully charged battery cell is about 2.1 volts. This can be measured with the help of a voltmeter. It can be observed that a charge of 0.001 volts of open circuit voltage is equivalent to a charge of 0.010 in the specific gravity of the electrolyte. Thus the gravity measurements can be indirectly made with a voltmeter also.
3. High Discharge Test
At the time of starting, the cranking motor draws a very heavy current due to which the cell voltage falls. To satisfy this condition, a high discharge test is made with the help of a cell voltage tester. It consists of a voltmeter connected to two legs with a resistance placed across them. When the two legs are pressed on cell terminals, a heavy current(150-200 amperes) flows through the cell voltage tester. The test is made for 5 seconds at the end of which the voltage does not fall below 1.5 volts, and the difference in cell voltage of various cells should not exceed 0.2 volts, otherwise, the battery is considered to be defective.
4. Cadmium Test
This test is done to ascertain whether the battery plates are defective or not. It is done with the help of a cadmium rod enclosed in a perforated ebonite tube. The rod is immersed in the electrolyte and connected to the negative terminal of a voltmeter. Its positive terminal is connected alternative to the positive and negative terminals of the battery cell. When connected with positive terminals, the voltage reading should not be less than 2.5 volts, a lower reading would indicate defective positive plates. When connected with negative terminals, the voltage reading should not be more than 0.2 volts, a higher one would indicate defective negative plates.
Ending this up
The temperature and the shocks coming from the roads are dangerous for the battery to keep its state optional. So checking the battery from time to time is the best option for a vehicle owner to keep the electrical system healthy.
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