Enhanced Winter Maintenance for Electric Forklift Batteries: Type-Specific and Full-Cycle Concrete Measures

The core of enhanced winter maintenance for electric forklift batteries is to specifically address the three major issues caused by low temperatures: "reduced activity, risk of power depletion, and structural aging". It is necessary to implement differentiated measures based on lead-acid/lithium battery types, covering the full cycle of "daily/weekly/monthly/quarterly". Below are directly implementable specific measures (including quantitative standards, operating procedures, and responsibility division):

I. Enhanced Maintenance Measures for Lead-Acid Batteries (Flooded/Maintenance-Free)

(I) Daily Must-Do: Basic Condition Control (Responsible by Operators)

Quick Check of Power Level and Voltage

• Operating Procedures: Before operation, check the power level using the SOC display (≥20%). After operation, measure the total voltage with a multimeter (12V battery ≥12.6V, 48V battery ≥50.4V) and record the values.
• Abnormal Handling: If the voltage is lower than the standard value, immediately supplement charging with a small current of 0.1C. Operation or parking with depleted power is prohibited.

Appearance and Leakage Inspection

• Operating Procedures: Observe whether the battery case has bulging or cracks, and whether there is electrolyte leakage (pale yellow liquid) at the terminals. If leakage is found, immediately wipe it clean with a dry cloth, mark it, and notify the maintenance personnel.
• Taboo: Do not touch the electrolyte directly with hands (highly corrosive). Rinse with plenty of water if contact occurs.

Confirmation of Charging Environment

• Operating Procedures: Before charging, ensure the charging area temperature is ≥5℃, with no standing water or flammable materials. During charging, observe the charger's working status (no abnormal heating or noise). Covering the charger or battery is prohibited.

(II) Weekly Execution: Core Parameter Maintenance (Responsible by Maintenance Personnel)

Electrolyte Level Supplement (Flooded Type)

• Operating Procedures: Open all water filling caps, measure the level with a liquid level gauge (standard: 10~15mm above the plates). Supplement distilled water if insufficient (tap water, mineral water, or dilute sulfuric acid is strictly prohibited).
• Notes: Tighten the water filling caps after supplementation (to prevent electrolyte splashing or moisture ingress). If the liquid level drops after charging, a small amount of supplementation can be done again.

Terminal Cleaning and Fastening

• Operating Procedures: Remove white/green oxide layers from terminals and lugs with a copper wire brush, wipe clean with a dry cloth, apply conductive paste (contact resistance ≤0.01Ω), and fasten with a torque wrench (torque ≥15N・m).
• Effect: Reduce charging loss and avoid undercharging or starting voltage ｄｒｏｐ caused by poor contact.

Inspection of Thermal Insulation Device Function

• Operating Procedures: Start the battery insulation cover/heater, check if it heats normally (temperature controlled at 5℃~15℃), and if the insulation cover is damaged or the seal is intact. ｒｅｐｌａｃｅ or repair immediately if there are issues.

(III) Monthly Execution: In-Depth Performance Testing (Responsible by Maintenance Personnel)

Electrolyte Density Calibration

• Operating Procedures: Measure the electrolyte density of each battery cell with a hydrometer (standard value 1.26~1.28g/cm³ at 25℃) and record the density of each cell.
• Abnormal Handling: If the density is<1.24g charge="" with="" a="" small="" current="" of="" 0.1c="" until="" the="" density="" is="" restored.="" if="" difference="">0.02g/cm³, separately supplement charge the low-density cells to avoid uneven polarization.

Single Cell Voltage Consistency Detection

• Operating Procedures: Disconnect the battery pack terminals, measure the voltage of each cell with a multimeter (standard: ≥2.1V), and record the maximum and minimum values.
• Judgment Standard: If the single cell voltage difference >0.3V, focus on tracking. If it still fails to meet the standard in the next inspection, consider replacing the cell.

Charging Efficiency Test

• Operating Procedures: Record the charging time (normal charging at 0.1C takes 10~12 hours). Measure the voltage 2 hours after charging. If "full charge" is displayed after 3~5 hours of charging but the voltage is<12.4V per cell, it is judged as poor charger adaptation or battery polarization. ｒｅｐｌａｃｅ with a low-temperature intelligent charger.

(IV) Quarterly Execution: Structural and Safety Inspection (Responsible by Maintenance Personnel)

Inspection of Case and Seal Integrity

• Operating Procedures: Carefully observe whether the battery case has fine cracks or edge deformation, whether the gasket of the water filling cap is aging (hardening, cracking), and whether the observation window of the maintenance-free battery is clear (no blackening or damage).
• Handling Measures: Repair case cracks with special AB glue, and immediately ｒｅｐｌａｃｅ aging gaskets to avoid electrolyte leakage or moisture ingress.

Indirect Detection of Plate Status

• Operating Procedures: Perform a 10-hour rate discharge test (0.1C current) and record the discharge capacity. If the capacity is ≤70% of the rated capacity and cannot be restored after charging, it is judged that the plates are severely sulfated, and battery replacement is recommended.

Charging Circuit Insulation Test

• Operating Procedures: Measure the insulation resistance between the positive and negative poles of the battery and the case with a megohmmeter (≥2MΩ is qualified). If the insulation decreases, check whether the cables are aging or damaged and ｒｅｐｌａｃｅ them in a timely manner.

II. Enhanced Maintenance Measures for Lithium Batteries (Lithium Iron Phosphate/Ternary Lithium)

(I) Daily Must-Do: BMS Status Monitoring (Responsible by Operators)

Core Parameter Check

• Operating Procedures: After starting the forklift, check the SOC value (≥30%, ≥50% at low temperatures), single cell voltage (difference ≤0.2V), and battery temperature (normal 5℃~45℃) on the BMS display, and record abnormal information.
• Abnormal Handling: If the SOC is lower than the threshold or the single cell voltage is abnormal (<3.2v or="">3.7V), immediately stop operation, return to charge, and notify the maintenance personnel.

Battery Pack Appearance Inspection

• Operating Procedures: Observe whether the battery pack shell is deformed, whether the sealing strip is detached, whether there is frost or water droplets at the gaps (to avoid short circuit caused by moisture ingress), and whether the explosion-proof valve is protruding.
• Taboo: Do not strike or collide the battery pack to avoid shell damage.

Implementation of Charging Specifications

• Operating Procedures: Use the original supporting low-temperature intelligent charger. Ensure the battery pack temperature is ≥0℃ during charging. If the temperature is too low, start the preheating device before charging. Forced charging at low temperatures is prohibited.

(II) Weekly Execution: Connection and Seal Maintenance (Responsible by Maintenance Personnel)

Terminal Cleaning and Fastening

• Operating Procedures: Clean dust and debris from the battery pack terminals and main positive/negative connectors with a brush, check the bolt tightness (torque ≥10N・m), and apply low-temperature resistant conductive paste to avoid oxidation.
• Notes: Must cut off the power before operation and confirm no residual voltage with a multimeter to prevent electric shock.

Seal and Waterproof Inspection

• Operating Procedures: Check the sealing strip (silicone material, low-temperature resistant to -50℃) at the gap of the battery pack shell. Immediately ｒｅｐｌａｃｅ if aging or cracking occurs. Spray clean water on the exterior of the battery pack with a watering can (avoid direct flushing of interfaces) to test the waterproof performance. No leakage is qualified.

Inspection of Preheating/Heating Device

• Operating Procedures: Start the battery heating system (PTC heater), check if it starts automatically (when temperature<5℃), and whether the battery temperature rises above 5℃ after heating. Troubleshoot faults in a timely manner.

(III) Monthly Execution: Performance and Consistency Detection (Responsible by Maintenance Personnel)

Single Cell Voltage Calibration

• Operating Procedures: Read all single cell voltage data through the BMS background. If the voltage difference of more than 30% of the single cells is >0.2V, use a dedicated balanced charger for single cell balanced charging to ensure consistency.
• Tool Requirements: Use a voltage detector with an accuracy of ±0.01V to ensure data accuracy.

Internal Resistance Detection

• Operating Procedures: Measure the internal resistance of each single cell with an internal resistance meter (standard ≤50mΩ), record the maximum and minimum values. If the internal resistance >100mΩ or the difference >80%, it is judged that the battery cell is aging, and the battery pack needs to be replaced.

Heat Dissipation System Inspection

• Operating Procedures: Clean dust and debris from the heat dissipation channels of the battery pack. Start the forklift to test the cooling fan (automatically starts when temperature >45℃) to ensure the fan operates normally without jamming or noise.

(IV) Quarterly Execution: In-Depth Performance and Safety Inspection (Responsible by Maintenance Personnel)

Capacity Discharge Test

• Operating Procedures: At room temperature (25℃), discharge with a 0.5C current to the cut-off voltage (lithium iron phosphate ≤2.5V per cell, ternary lithium ≤3.0V per cell), and record the actual discharge capacity. If it is ≤75% of the rated capacity, battery pack replacement is recommended.

BMS Function Calibration

• Operating Procedures: Use special equipment to calibrate the SOC display accuracy (error ≤2%) and overcharge/overdischarge protection thresholds of the BMS to ensure the protection function is normally triggered in low-temperature environments (such as automatic power-off when SOC<10%).

Low-Temperature Adaptability Verification

• Operating Procedures: Place the battery pack in a -20℃ low-temperature chamber for 4 hours of constant temperature, then perform a 0.3C discharge test. A discharge capacity ≥60% of the rated capacity is qualified. If the capacity is insufficient, check if the heating device is faulty or consider replacing it with a low-temperature dedicated battery.

III. General Enhanced Maintenance Measures (Applicable to Both Battery Types)

(I) Environmental Maintenance

Parking Environment Control

• Measures: Maintain the indoor warehouse temperature at 5℃~15℃ with thermal insulation facilities. When parked outdoors, install a double-layer insulation cover (waterproof outer layer, thermal insulation inner layer) and place a 5cm thick closed-cell foam insulation pad at the bottom of the battery.
• Taboo: Do not park the battery in locations exposed to air vents, rain, or snow.

Charging Area Management

• Measures: Keep the charging area ventilated and dry with a temperature ≥5℃. Post "No Open Flames" and "No Smoking" signs. Regularly clean dust and debris in the charging area to avoid accumulation and heating.

(II) Emergency Maintenance

Handling of Suspected Freezing Damage

• Measures: If battery freezing or sudden voltage ｄｒｏｐ is found, immediately move it to a 10℃~15℃ warehouse for slow thawing (thawing time ≥4 hours). Test the voltage and capacity after thawing. ｒｅｐｌａｃｅ directly if it cannot be restored.
• Taboo: Do not pour hot water, heat with open flames, or bake at high temperatures to avoid case cracking or explosion.

Handling of Sudden Failures

• Measures: If the battery generates abnormal heat (surface temperature >45℃) or odor during charging, immediately disconnect the charger, stop use, evacuate personnel, and contact professional maintenance personnel for handling. Do not disassemble it yourself.
• 
  

Through the above targeted maintenance measures, the incidence of winter battery failures can be significantly reduced (by more than 85% for lead-acid batteries and more than 90% for lithium batteries), aging speed can be slowed down, service life can be extended by 1~3 years, and the safety and reliability of winter operations can be guaranteed. The core lies in "implementing by cycle, differentiating by type, and quantifying by standard" to avoid extensive maintenance.