Systematic Solution for Improving the Endurance of Electric Forklifts Through Vehicle Maintenance
Vehicle maintenance is the core foundation for ensuring stable endurance of electric forklifts and reducing energy consumption loss. The core logic is to reduce mechanical friction loss, improve the efficiency of the electric drive/hydraulic system, and ensure the stable operation of the battery and electronic control system. Below is a sub-system, executable maintenance plan with cycles and acceptance criteria.
I. Special Maintenance of the Battery System (Core of Endurance, Accounting for Over 30% of Energy Consumption Impact)
The battery is the source of endurance. The focus of maintenance is to eliminate contact resistance, control temperature, balance battery cells, and avoid overcharging and over-discharging.
Terminal and Connection System Maintenance
- Maintenance Cycle: Daily pre-shift inspection, weekly in-depth cleaning, monthly tightening and testing
- Operation Points: Remove oxides and dirt from battery terminals and busbars with a special cleaner and copper brush; tighten bolts to the manufacturer's standard torque (usually 10–15 N·m); test terminal contact resistance (≤5 mΩ) to avoid heat loss during high-current operation.
- Acceptance Criteria: No oxidation or looseness of terminals; voltage deviation of single cells ≤0.05 V.
Battery Cell and BMS Maintenance
- Maintenance Cycle: Monthly balanced charging, quarterly voltage/internal resistance testing of single cells, semi-annual BMS calibration
- Operation Points: Perform a full charge-discharge cycle plus balanced charging for lead-acid batteries every month; monitor SOC/SOH of lithium batteries through BMS and test the internal resistance of single cells (replace cells if the internal resistance of lithium batteries changes abruptly by ≥20%); calibrate the voltage, current and temperature sensors of BMS to avoid overcharging and over-discharging caused by misjudgment.
- Acceptance Criteria: Internal resistance difference of single cells ≤10%; deviation between BMS data and measured values ≤2%.
Temperature and Environmental Control
- Maintenance Cycle: Daily environmental inspection; additional temperature control measures in high/low temperature seasons
- Operation Points: Ensure no blockage of battery compartment vents and clean the filters of liquid cooling/air cooling systems weekly; prioritize indoor charging and parking in low-temperature environments (<10°C) to avoid capacity degradation; enhance ventilation or activate liquid cooling in high-temperature environments (>35°C) to prevent thermal runaway.
- Acceptance Criteria: Battery operating temperature 20–25°C; temperature difference ≤3°C.
II. Maintenance of Travel and Transmission System (Reducing Friction Loss, Accounting for Over 25% of Energy Consumption Impact)
The rolling/friction resistance of the travel system directly affects energy consumption, and the efficiency of the transmission system determines the loss of converting electrical energy into mechanical energy.
Tire and Wheel Hub Maintenance
- Maintenance Cycle: Daily tire pressure inspection, weekly tread inspection, semi-annual wheel hub bearing maintenance
- Operation Points: Maintain tire pressure within ±5% of the manufacturer's rated value to avoid increased rolling resistance due to low pressure; timely replace tires with uneven tread wear or tread depth <3 mm; fill wheel hub bearings with special lubricating grease according to the manufacturer's specifications to avoid friction and heat caused by over-lubrication or insufficient lubrication.
- Acceptance Criteria: Stable tire pressure; no abnormal tread wear; no heating of wheel hubs; rolling resistance ≤ manufacturer's standard value.
Drive Axle and Transmission Component Maintenance
- Maintenance Cycle: Oil change every 500 hours; transmission efficiency testing every 1000 hours
- Operation Points: Replace with special gear oil with high viscosity index (select low-temperature type for low-temperature environments); check that there is no leakage of drive axle oil seals and no pitting or wear of gears; optimize the transmission ratio to ensure matching between the motor and the drive axle, with transmission efficiency ≥98%.
- Acceptance Criteria: No leakage; clean gear oil without impurities; transmission efficiency meets the standard.
III. Hydraulic System Maintenance (Reducing Standby/Operation Loss, Accounting for Over 20% of Energy Consumption Impact)
The hydraulic system is a high-energy-consumption component of electric forklifts. The focus of maintenance is to reduce leakage, lower hydraulic resistance, and improve the efficiency of pumps and valves.
Hydraulic Oil and Filter Maintenance
- Maintenance Cycle: Oil change every 800 hours; filter replacement every 400 hours; daily oil level inspection
- Operation Points: Select low-viscosity, high-wear-resistance hydraulic oil recommended by the manufacturer (select low-temperature hydraulic oil for low-temperature environments); clean the oil tank when replacing the filter to prevent impurities from entering the system; maintain the oil level between the upper and lower limits of the oil gauge to avoid pump idling due to insufficient oil.
- Acceptance Criteria: Hydraulic oil cleanliness below NAS Class 8; no leakage; oil level meets the standard.
Pump, Valve and Pipeline Maintenance
- Maintenance Cycle: Pressure testing of pumps and valves every 1000 hours; monthly inspection of pipelines and joints
- Operation Points: Adjust the working pressure of the hydraulic system to the manufacturer's rated value (avoid energy loss caused by overpressure); check that there is no internal/external leakage of pumps, valves and cylinders, and replace aging seals in a timely manner; ensure no bending or blockage of pipelines and that joint torque meets the standard.
- Acceptance Criteria: No leakage; stable working pressure; uniform lifting/lowering speed.
IV. Maintenance of Electronic Control and Energy Recovery System (Improving Electric Energy Utilization Rate, Accounting for Over 15% of Energy Consumption Impact)
The electronic control system is the "command center" of energy consumption, and the energy recovery system can directly improve endurance. The focus of maintenance is to ensure precise control and trouble-free operation of the system.
Electronic Control Unit (ECU) and Sensor Maintenance
- Maintenance Cycle: Semi-annual cleaning and testing; annual calibration
- Operation Points: Clean dust in the electric control cabinet and check that the cooling fan is unobstructed and runs at normal speed; test the signal accuracy of the accelerator pedal, brake pedal and tilt sensor, and calibrate the signal threshold; check that the wiring harness is not damaged or poorly connected, and that the joints have good waterproof sealing.
- Acceptance Criteria: No ECU alarms; sensor signal deviation ≤1%; no wiring harness faults.
Energy Recovery System Maintenance
- Maintenance Cycle: Recovery efficiency testing every 1000 hours; semi-annual inspection of braking resistors/inverters
- Operation Points: Check the parameter settings of the energy recovery system (such as recovery intensity and SOC threshold); test the electric energy feedback efficiency during braking (≥15%); check that there is no ablation of braking resistors and no overheating of inverters to ensure stable storage of recovered energy.
- Acceptance Criteria: Normal energy recovery during braking; feedback efficiency meets the standard; no fault alarms.
V. Maintenance Cycle and Effect Evaluation
| Maintenance System | Core Maintenance Items | Implementation Difficulty | Effectiveness Cycle | Endurance Improvement Range |
|---|---|---|---|---|
| Battery System | Terminal cleaning + balanced charging + temperature control | Medium | 1–2 weeks | 15%–20% |
| Travel and Transmission System | Tire pressure adjustment + gear oil replacement + transmission efficiency optimization | Low | 1 month | 5%–10% |
| Hydraulic System | Hydraulic oil replacement + pump and valve leakage inspection | Medium | 1 month | 5%–8% |
| Electronic Control and Recovery System | ECU cleaning + recovery efficiency testing | Medium | 2 weeks | 5%–10% |
VI. Implementation Suggestions
- Formulate Standardized Maintenance SOP: Compile the Electric Forklift Endurance Optimization Maintenance Manual according to the above cycles and operation points, clarifying responsible persons, acceptance criteria and record forms.
- Hierarchical Maintenance Management: Daily pre-shift inspections (performed by drivers), weekly/monthly in-depth maintenance (performed by maintenance teams), quarterly/annual special testing (performed by manufacturer after-sales service or third-party institutions).
- Data-driven Monitoring: Real-time monitor energy consumption, battery SOC and system faults through the fleet management system. Combine with maintenance records to analyze the causes of abnormal energy consumption and continuously optimize the maintenance plan.
