Accelerated battery self-discharge
serviceable «underserved» battery when stored or engine off (when there is no recharging from the generator) discharges gradually by about 0.2... 0.3% per day. If the battery discharges more than 10% within a month at ambient temperature (20±5) °C, then such a self-discharge is considered accelerated and is a sign of battery failure.
Causes of accelerated self-discharge and ways to eliminate it:
- contamination of the electrolyte with foreign impurities. When preparing the electrolyte, only chemically pure sulfuric acid and distilled water should be used. When checking the level and density of the electrolyte, it is required to keep it clean and prevent various substances from entering the battery;
- electrolyte contamination of the battery surface. In this case, the battery self-discharges through the electrolyte on the surface of the battery. To eliminate it, it is necessary to monitor the cleanliness of the battery surface and remove the electrolyte with a rag moistened with a 10% aqueous solution of ammonia or baking soda. In this case, it is necessary to ensure that soda or ammonia does not get into the battery cells.
Sulfation of battery plates
This malfunction lies in the fact that large crystals of lead sulfate form on the surface of the plates, which do not disintegrate when the battery is charged. The pores of the plates become narrower and the access of the electrolyte to the inside of the active mass becomes more difficult. As a result, the battery capacity is significantly reduced, it is quickly charged to a high voltage and discharged even faster. This battery needs to be replaced.
Causes of sulfation and how to eliminate it:
- deep discharges of the battery and long-term storage of it in a discharged state. Prevent a strong discharge of the battery, control the degree of discharge by the density of the electrolyte and recharge the battery in a timely manner;
- operation of a battery with a reduced level and density of the electrolyte. Timely control the level and density of the electrolyte and bring them to normal;
- systematic undercharging of the battery, operation of an incompletely charged battery. Bring the battery to the end and do not allow the needle of the car's voltmeter to be in the red zone (at the beginning of the scale), indicating that the battery is not charged.
Short circuits inside the battery
During operation, wear of the plates occurs, which is characterized by gradual chipping and sliding of the active mass. Improper operation of the battery accelerates this process, precipitation accumulates in large quantities at the bottom and closes opposite plates. Symptoms of a malfunction - a sharp decrease in battery capacity and voltage, too fast discharge. If a short circuit occurs in all elements, then there will be no voltage at the battery terminals. Such a battery must be returned for repair or replaced with a new one.
Causes of a short circuit and how to eliminate it:
- charge the battery with high current and at high temperature, frequent recharges. As a result of this, warping and chipping of the plates, damage to the separators occur. Strictly observe the recommended battery charge mode, avoid overcharging, during which «boiling» electrolyte;
- electrolyte freezing. In this case, the plates and separators are destroyed, and the battery case may be damaged. Monitor the density of the electrolyte and prevent it from decreasing below that recommended for each climatic region;
- strong vibration of the battery due to the loosening of its fastening on the car. This leads to intensive shedding of the active mass of the plates. Make sure the battery is secure.
Spilling electrolyte from battery cells
After driving a car, electrolyte remains on the surface of the battery. Electrolyte drops fall on car parts and lead to their corrosion.
Causes of malfunction and solutions:
- an increased level of electrolyte in the battery cells, leading to its splashing. Check and bring the electrolyte level to normal;
- excessively high generator voltage. In this case, there is a violent «boiling» electrolyte in the battery and its splashing. Replace generator voltage regulator. When operating the car, make sure that the voltmeter needle is not in the red zone (at the end of the scale);
- battery sulfation. The battery charges quickly and starts to copious «boiling» electrolyte, causing it to splash out.