I. Inspection and Judgment of Common Faults

1.1 Reduced Capacity

• a. Sulfation;
• b. Electrolyte contamination;
• c. Whether the battery has a local short circuit;
• d. Grid corrosion, plate fracture, active material shedding, etc., occurring at the end of its normal service life.

1.2 Abnormal Voltage

1.3 High Electrolyte Temperature

1.4 Why Do Lead-Acid Batteries Explode, and How to Prevent It?

• A. Control the charging capacity and avoid overcharging to reduce gas emission.
• B. Strictly prohibit open flames near the battery during charging and maintain ventilation.
• C. Ensure that the connection points are firm during charging to prevent sparks from loose connections.
• D. Adopt constant voltage and current-limiting charging, which produces less gas.
• E. Prevent short circuits in the circuit that may generate sparks, leading to fire and explosion.
• F. Ensure that the vent holes are unobstructed. Excessively high internal pressure will cause the battery to bulge, crack, or even explode.

1.5 What Causes the Shedding of Active Materials on Battery Plates, and How to Judge It?

• (1) Excessively large charging current and prolonged charging time lead to frequent overcharging. This causes excessive oxidation and loosening of the active materials, corrosion of the grid (losing the ability to support the active materials), and the generation of a large amount of hydrogen and oxygen gases due to increased temperature, which excessively scour the active materials and cause shedding.
• (2) Frequent over-discharging generates a large amount of lead sulfate, resulting in excessive volume expansion and decreased bonding force.
• (3) Frequent charging at high temperatures causes the positive active materials to form a soft mud-like substance, leading to shedding.
• (4) Long-term high-current discharge causes the plates to bend, reducing the adhesion of the active materials.
• (5) Excessive vibration of the battery on the vehicle/equipment leads to shedding.
• (6) Impurities entering the battery: alkaline substances can cause expansion and shedding of the porous metallic lead on the negative plate.

1.6 Anatomical Inspection of Active Material Shedding on Plates

• (1) A large amount of brown sediment accumulates at the bottom of the battery case in a short period of time, indicating shedding from the positive plates, which is caused by excessive charging current or frequent overcharging.
• (2) White sediment is caused by frequent over-discharging (resulting in the formation of lead sulfate precipitation from active materials) or impurities in the electrolyte, especially excessive chlorine leading to the formation of lead chloride precipitation.
• (3) Brown, light blue, or white sediment indicates the entry of harmful impurities such as iron and copper into the battery.
• (4) If the shed material is pasty, it indicates that the battery was charged with an excessively large current or at an excessively high temperature. If the sediment is lumpy, it indicates impure electrolyte causing plate corrosion and shedding.

1.7 How to Prevent Abnormal Shedding of Plate Active Materials During Use?

• (1) Do not use an excessively large charging current or prolong constant current charging unnecessarily. Stop charging once the terminal voltage rises and stabilizes to prevent excessive oxidation and loosening of the active materials (losing bonding force). In addition, avoid excessively high temperatures to reduce gas emission and prevent scouring of the active materials.
• (2) Avoid over-discharging to prevent the generation of a large amount of lead sulfate (excessive expansion and loss of bonding force with active materials). During use, retain a certain amount of power in the battery (only use 70%—80% of its capacity).
• (3) Do not use an excessively low electrolyte density. In severe cold seasons, a density lower than 1.050 g/cm³ is prone to freezing, causing the active materials to crack due to ice crystal expansion.
• (4) Avoid excessively high temperatures during charging. If the temperature exceeds 50℃, the positive grid will corrode, and lead dioxide will easily soften and shed. Cooling measures should be taken during the initial charging of new batteries.
• (5) When installing the battery on a vehicle, use shockproof pads to prevent excessive vibration and reduce active material shedding.
• (6) Prevent any impurities from entering the battery, otherwise, the active materials on both electrodes will shed.
• (7) During high-current starting and discharging, the starter motor should not operate for more than 3—5 seconds at a time. For the second start, an interval of more than 5 seconds is required; do not start continuously.

II. Battery Maintenance Methods

2.1 Incoming Inspection and Storage Management of Batteries

• Check whether the incoming goods are damaged. The battery case surface and the joints with positive and negative terminals should be free of acid leakage, cracks, bumps, and dirt. Residual acid may indicate battery damage or failure to clean the acid after charging.
• Check the battery state indicator (eye):
  • Green: The battery is fully charged and can start the car normally.
  • Black: The battery is undercharged and needs to be recharged.
  • White: The battery is scrapped and needs to be replaced.
• The length of the forklift's forks should preferably match the width of the pallet to prevent damage to the battery.
• Store batteries centrally and separately.
• Implement the first-in, first-out (FIFO) principle.
• Do not store batteries in high-temperature areas. If the storage environment temperature is below -15℃, the batteries should be stored in a warm warehouse (warehouse temperature ≤ 20℃).

2.2 Battery Installation

• The battery inclination should not exceed 40 degrees.
• Do not invert or lay the battery sideways.
• Check the eye before installation to confirm it is green.
• Check and clean the battery tray for screws or nuts to prevent secondary damage to the battery.
• Do not install batteries with a black eye (if the eye is black and the production batch or date is recent, the battery may be defective).
• Do not install leaking batteries.
• Do not strike or twist the terminals during installation.

2.3 Battery Maintenance for Stored Vehicles

• If the vehicle is stored for more than 15 days, disconnect the negative battery cable.
• Check the battery eye status every three months:
  • Green eye: The battery is normal.
  • Black eye: The battery is undercharged and must be recharged.
• For vehicles with the battery cable not disconnected, check the battery eye status every month. Undercharged batteries (black eye) should be recharged according to the recharging procedure.

2.4 Maintenance Requirements for Batteries by Agents and Distributors

• For stored vehicles and display vehicles parked for more than 15 days, remove the negative battery cable.
• The battery installation should be secure; the battery case surface and the joints with positive and negative terminals should be free of acid leakage, cracks, bumps, and dirt.
• Check the battery state indicator (eye):
  • Green: The battery is fully charged and can start the car normally.
  • Black: The battery is undercharged and needs to be recharged.
  • White: The battery is scrapped and needs to be replaced.
• Check the battery eye status every three months:
  • Green eye: The battery is normal.
  • Black eye: The battery is undercharged and must be recharged.
  • Batteries of stored vehicles must be recharged every six months.
• For vehicles with the battery cable not disconnected, check the battery eye status every month. Undercharged batteries (black eye) should be recharged according to the recharging procedure.
• Before vehicle delivery, check to ensure the battery eye is green. Do not directly deliver vehicles started by borrowing batteries from other vehicles to customers.

III. Battery Safe Operation Guidelines

3.1 Electrical Energy

• If the positive and negative terminals of the battery are accidentally short-circuited by metal conductors (such as metal tools, metal wires, metal accessories, etc.), an external short circuit of the battery will occur. This will generate an electric arc, causing the terminals to melt and molten lead alloy to splash. In severe cases, a large amount of heat will be generated, leading to combustion.
• Prevention: When using metal tools for battery assembly or metal wires for fault diagnosis, avoid direct short-circuiting of the positive and negative battery terminals.
• Protection: Wear protective goggles and gloves.
• Emergency Treatment: In case of combustion, use an adjustable wrench or other tools to immediately disconnect the metal conductor causing the external short circuit. Do not touch it with bare hands and use fire-extinguishing materials to extinguish the fire.

3.2 Sulfuric Acid

• If the battery falls or is overcharged, the case may crack, and sulfuric acid may leak or splash from the crack.
• Prevention: Handle with care; place vertically upward; recharge according to the recharging procedure.
• Protection: Wear protective goggles and acid-resistant clothing.
• Emergency Treatment: If sulfuric acid comes into contact with the skin, immediately rinse the affected area with a large amount of water and remove contaminated clothing. If sulfuric acid enters the eyes, immediately rinse with clean water for at least 10 minutes. If sulfuric acid is accidentally splashed into the mouth, drink a large amount of water or milk. Seek medical attention if necessary.

3.3 Emitted Gases

• During battery charging and testing, a mixture of oxygen and hydrogen will be emitted from the vent holes. If the hydrogen concentration in the environment exceeds 4%, contact with open flames, sparks, or high heat will cause an explosion.
• Prevention: Maintain ventilation at the charging location. Prohibit smoking and prevent sparks and open flames. After charging is completed, wait for half an hour (to allow sufficient release of internal hydrogen) before moving the battery to prevent the plates from being exposed when the internal liquid shakes, causing internal sparking and igniting hydrogen.
• Protection: Wear protective goggles and acid-resistant clothing.
• Emergency Treatment: If the battery explodes and a large amount of sulfuric acid splashes, the operator should immediately rinse the affected area with water. If necessary, immediately send personnel burned by sulfuric acid to the hospital for treatment.