Common faults and troubleshooting methods of batteries

1、 Common faults and troubleshooting methods

1. Insufficient capacity (unable to meet backup time)

• Phenomenon:

• Voltage drops sharply during discharge, and the standby time is lower than the design value;

• The capacity of the nuclear capacity test does not meet the standard (such as below 80% of the rated capacity).

• Reason:

• Long term float charging leads to passivation of active substances ("float charging deactivation");

• Aging or poor consistency of individual batteries;

• The ambient temperature is too high (accelerated aging) or too low (temporary decrease in capacity).

• resolvent:

• Regular nuclear discharge: Conduct capacity testing every 1-2 years to activate the battery;

• Balanced charging: evenly charge the battery pack to restore consistency;

• Replace outdated cells: Remove cells with severely insufficient capacity.

2. Abnormal voltage of individual batteries

• Phenomenon:

• The individual voltage is too high or too low (deviation from the average value>± 5%);

• The voltage fluctuates greatly during float charging.

• Reason:

• The internal resistance of the battery increases due to aging and sulfurization;

• Poor contact or corrosion at the connection point;

• The parameter settings of the charger are incorrect (such as excessively high average charging voltage).

• resolvent:

• Internal resistance test: Use the battery internal resistance meter produced by Yangzhou Haiwo to detect abnormal cells;

• Clean the connection terminals: remove the oxide layer and apply Vaseline;

• Adjust charging parameters: Set the float/equalization voltage according to the battery technical manual.

3. Poor uniformity of battery pack

• Phenomenon:

• The voltage difference between individual cells in the battery pack is large (such as>0.2V);

• During discharge, some individual cells reach the cut-off voltage ahead of schedule.

• Reason:

• Mixing old and new batteries;

• Long term unbalanced charging;

• Uneven distribution of environmental temperature.

• resolvent:

• Replace units with poor consistency;

• Regular equal charging (such as once every quarter);

• Optimize battery layout: Ensure even heat dissipation and avoid local high temperatures.

4. Leakage or bulging of the shell

• Phenomenon:

• Deformation, bulging or leakage at the sealing of the battery casing;

• Leakage caused corrosion of the battery rack.

• Reason:

• Overcharging causes the inability to release internal gas (safety valve failure);

• High temperature environment accelerates electrolyte evaporation;

• Mechanical vibration causes cracks in the shell.

• resolvent:

• Immediately replace the leaking battery (the electrolyte is highly corrosive);

• Check the parameters of the charger: ensure that the float charging voltage is ≤ 2.25V per unit (lead-acid battery);

• Strengthen ventilation and heat dissipation: Control the ambient temperature at 20-25 ℃.

5. Grounding fault

• Phenomenon:

• DC system insulation monitoring alarm;

• Abnormal ground voltage of the battery pack (such as unbalanced positive and negative pole to ground voltage).

• Reason:

• Dirty battery surface leads to insulation degradation;

• Electrolyte leakage causes a ground short circuit.

• resolvent:

• Clean the surface of the battery: wipe it with a dry cloth to keep it dry;

• Identify the leakage point: isolate the faulty battery and replace it;

• Regularly check the insulation resistance (standard: ≥ 1M Ω).

2、 Special maintenance requirements for power system batteries

1. Online monitoring:

• Install an online monitoring system for batteries to monitor real-time parameters such as cell voltage, internal resistance, temperature, etc;

• Set threshold alarms (such as voltage exceeding limits or sudden changes in internal resistance).

2. Nuclear discharge test:

• At least one deep discharge (80% -100% capacity) per year to verify backup time;

• Use professional load cabinets to avoid human operation errors.

3. Temperature management:

• Install air conditioning or cooling fans, and control the temperature of the battery room at 20-25 ℃;

• Avoid direct sunlight or proximity to heat sources.

4. Explosion proof and safety:

• Valve regulated lead-acid batteries (VRLA) or lithium batteries should be equipped with BMS;

• The battery room is equipped with a hydrogen concentration detector (which releases hydrogen gas when lead-acid batteries are charged).

IIICommon faults and troubleshooting methods of batteriesTypical fault handling process

1. Fault alarm: locate abnormal cells or battery packs according to the monitoring system;

2. Preliminary inspection:

• Measure individual voltage and internal resistance;

• Check if the connection points are loose or corroded.

3. Isolation fault: Disconnect the faulty battery to avoid affecting the overall system;

4. Repair or replace:

• Mild vulcanization: uniform charging repair (2.35-2.4V/monomer, lasting 8-12 hours);

• Severe aging: replace directly.

5. Recording and analysis: Record the causes of faults and optimize maintenance strategies.

4、 When is it necessary to replace the battery pack?

• Capacity attenuation to below 80% of rated value;

• The internal resistance of a single battery exceeds the initial value by 50%;

• Physical damage such as leakage and swelling cannot be repaired;

• The design lifespan expires (8-10 years for lead-acid batteries and 10-15 years for lithium batteries).

The power system battery is a key equipment to ensure the safety of the power grid, and its lifespan needs to be extended through regular monitoring, professional maintenance, and standardized operation. If the fault is complex or involves a high-voltage system, it must be operated by professionals!