Common faults and solutions of batteries
Common faults of batteries include internal faults and external faults.
External failures: shell cracks, pole corrosion, pole looseness, and dry cracking of sealant.
Internal failure: electrode plate vulcanization, active material shedding, electrode plate grid frame corrosion, electrode plate short circuit, self-discharge, electrode plate arching.
1. Plate vulcanization
1. Concept: The phenomenon of the formation of white coarse-grained lead sulfate on the plate is called vulcanization.
2. Hazard: Coarse-grained lead sulfate has poor electrical conductivity and is difficult to restore under normal charging. The grains are coarse and bulky, blocking active material pores and increasing internal resistance.
3. Fault characteristics
(1) A layer of white coarse-grained lead sulfate is formed on the pole plate;
(2) The internal resistance is large when discharging , The voltage drops sharply, and the starting current cannot be continuously supplied;
(3) When charging, the internal resistance is large, and the charging voltage of a single cell quickly rises to more than 2.8V, the density rises slowly, and the temperature rises quickly. Boiling occurs prematurely.
(4) When tested with a high-rate discharge meter, the single-cell voltage drops significantly.
4. Reasons for failure
(1) Insufficient charging, long-term storage or discharging, and not charging in time after discharging; (PbSO4 dissolves when the temperature is high, and precipitates when the temperature is low Large-grain PbSO4 is on the surface of the electrode plate)
(2) The electrode plate is exposed to the electro-liquid surface and oxidizes; (the upper part of the negative plate is often exposed to the liquid surface and oxidized due to the peak wave during the driving process Generate coarse-grained PbSO4)
(3) If the electrolyte density is too high, a potential difference is easily formed inside the battery, which will cause self-discharge and cause PbSO4 to recrystallize;
(4) Electrolyte Impurity causes self-discharge, causing PbS04 to recrystallize.
5. Prevention and remedy
The battery should be in a fully charged state, and the battery should be recharged in time after it is discharged; the electrolyte density should be appropriate; the level of the liquid should meet the requirements; it has been vulcanized For the lighter battery, use the desulfurization charging method to eliminate, and the severer battery will be scrapped.
1. Phenomenon: The starter rotates slowly and weakly, the light is dim, and the horn is quiet after the battery with sufficient power is parked for a day. When the capacity of a fully charged battery decreases by more than 2% per day and night, it should be regarded as self-discharging.
(1) The external circuit is short-circuited or not turned off;
(2) The surface of the battery is dirty;
(3) Internal short circuit (damaged partitions, active material falling off);
(4) Impure electro-hydraulic. (When the iron content reaches 1%, the battery will be discharged all day and night)
(5) The surface of the battery is not clean;
(6) The electrode plate welding slag causes a short circuit.
3. Fault diagnosis and troubleshooting
①Clean the outside of the battery;
②Check whether the wire is short-circuited to the ground; ③Check Is there any electrical equipment that has not been turned off;
4. Inspection method: turn off all electrical equipment, remove the wire on a terminal of the battery to test fire, if there is fire, it is a circuit problem; if there is no fire , The surface of the battery is dirty or the internal short circuit.
①Special battery sulfuric acid and distilled water must be used;
②The container for electrolyte and distilled water must be made of non-metallic acid-resistant materials; ③Keep the battery surface clean and dry, and prevent harmful impurities from falling into the pool.
3. The active material falls off
1. Fault characteristics
The output capacity of the battery decreases, the electrolyte is turbid during charging, and the brown material rises from the bottom.
2. Causes of failure
(1) The charging current is too large, and the overcharging time is too long (2) Low temperature and large current discharge, causing the plate to arch (3) When the car is running Bumps, vibrations, and shocks (4) The electro-hydraulic density is often too large, corroding the grid.
3. Elimination method
Dismantle and clean. If the active material falls off less, it can be packaged and reused; if there is a lot of fall off, replace the pole plate.
(1) Don’t charge;
(2) Charging current is not too large
(3) Don’t discharge, Discharge strictly according to the specified termination voltage (4) Use the starter according to the regulations
(5) Distilled water is generally added when adjusting the electro-liquid level, without sulfuric acid.
Four. Short circuit of the pole plate
1. Fault characteristics
The open-circuit terminal voltage is too low, the starter is weak, and the temperature is high and the voltage is low when charging. The density rises slowly or does not rise, there are few bubbles, no bubbles, or bubbles are generated too late.
2. Cause of failure
(1) The active material falls off too much, and the positive and negative plates are connected after deposition. (Must be disassembled and inspected)
(2) The partition is damaged and leaks or short-circuits.
(1) Excessive shedding of active material—discharge cleaning (2) Replacement when the partition is damaged
V. Battery capacity decrease
1) Phenomenon: Use a high-rate discharge meter to measure the single-cell voltage <1.5V; after fully charged, the battery will be insufficient after a short period of time, and the starter will run slowly and weakly, even The crankshaft of the engine cannot be driven to rotate, the sound of the horn is small, and the light is dim.
①The battery has been discharged and half-discharged for a long time, and the electrode plates are vulcanized (a layer of white coarse-grained lead sulfate is formed on the surface, which seriously affects the charging and discharging effect).
②The starter is often used for a long time and discharges with a large current. ③The charging voltage of the generator is too low, and the battery is often under-charged.
④The electro-hydraulic density is too high, causing the plate to vulcanize. ⑤The electro-hydraulic density is too low, resulting in a decrease in capacity. ⑥ The active material falls off, resulting in a decrease in capacity.
3) Fault diagnosis and troubleshooting
Diagnosis: When the battery cell voltage is lower than 1.5V measured by the high-rate discharge meter, it indicates the capacity insufficient.