Standard Operating Protocol for Preventing and Controlling Under-Voltage Operation of Electric Forklift Batteries in Winter

1. Protocol Objectives

2. Core Control Measures

2.1 Pre-operation: Power Prediction and Planning

Responsible Party: Forklift Operators

Implementation Frequency: Daily Pre-shift

1. 1.Power Baseline Verification

2. Confirm the initial power through the dashboard or Battery Management System (BMS) before startup. In winter, forklifts are only allowed to start operation if the initial power is not less than 80%.If the initial power is below 80%, operation is prohibited, and charging must be performed immediately. Charging shall comply with the standard of "charging room temperature 10℃–25℃ + 1-hour floating charge".

3. 2.Task-Power Matching

4. Calculate the estimated power consumption based on the task volume. The unit task power consumption in winter is 30%–50% higher than that in summer, so the calculation shall be based on 1.5 times the summer power consumption.Example: If transporting 100 pallets consumes 40% of power in summer, no less than 60% of power shall be reserved in winter. If the power is insufficient, split the task and conduct operations in batches.

5. 3.Low-Temperature Power Correction

6. When the operating environment temperature is below 5℃, increase the reserved power by an additional 10%. When the temperature is below -10℃, suspend outdoor operations, move the forklift to indoor areas, and recalculate the required power.

2.2 In-operation: Real-Time Monitoring and Early Warning

Responsible Party: Forklift Operators + Team Leaders

Implementation Frequency: Entire Operation Duration

1. 1.Power Monitoring Frequency and Threshold

2. Check the power level once after completing each batch of tasks (or every 30 minutes). Set 30% power as the early warning threshold. Stop operation immediately and return to the charging area once the threshold is reached.Prohibit "forced operation": In winter, the power drops from 30% to 0% twice as fast as in summer. When the remaining power is 30%, the battery voltage begins to ｄｒｏｐ sharply, and continuous use will cause deep discharge.

3. 2.Avoid High-Current Discharge Behaviors

4. Prohibit sudden acceleration, frequent start-stop, and overloading operations. These behaviors will cause instantaneous high-current discharge, accelerate power consumption, and damage the internal structure of the battery.Strictly control the winter load within 80% of the rated capacity to reduce battery load pressure.

5. 3.Handling of Abnormal Power ｄｒｏｐ

6. If an abnormal situation occurs where "power drops by more than 10% within 10 minutes", stop the machine immediately for inspection: Check for battery short circuits, loose and overheating terminals, etc. Report to the equipment maintenance personnel for handling, and prohibit further use.

7. 4.Team Leader Inspection and Supervision

8. Team leaders shall inspect the operation site once per hour, verify the forklift power level and operation progress, and promptly remind vehicles approaching the early warning threshold to return for charging.

2.3 Post-operation: Charging Management and Storage Support

Responsible Party: Equipment Maintenance Personnel

Implementation Frequency: Daily Post-shift

1. 1.Mandatory Charging System

2. After the forklift returns to the depot, it must be connected to the charger within 2 hours regardless of the remaining power. "Overnight storage with under-voltage" is strictly prohibited.Strictly implement the winter charging standards: Adopt staged charging for lead-acid batteries and perform 1-hour floating charge after the green light is on; enable low-temperature protection mode for lithium batteries, and prohibit charging when the temperature is below 0℃.

3. 2.Maintenance of Batteries for Long-Term Non-use

4. If the forklift is not used for more than 2 days, charge the battery to 80%–90% before storage, and maintain the storage environment temperature at 5℃–20℃.Maintenance personnel shall check the power level of idle batteries once a week and recharge them in a timely manner if the power is below 70%.

5. 3.Charging Status Monitoring

6. Install temperature and humidity recorders and power monitoring systems in the charging room to monitor the charging progress of each forklift in real time and avoid the situation of "power cut-off before full charge".

3. Technical Support Measures

1. 1.Install Power Early Warning Devices

2. Install audible and visual alarms on forklifts, which will automatically alarm when the power drops to 30% to remind operators to stop the machine for charging. Calibrate the alarm sensitivity once a month.

3. 2.Optimize Battery Management System (BMS) Parameters

4. For lithium batteries, adjust BMS parameters in winter: Limit the maximum discharge current to 0.5C of the rated current, set low-temperature discharge protection, and automatically cut off the discharge circuit when the temperature is below -10℃.

5. 3.Establish Power Usage Ledger

6. Record the initial power, operational power consumption, remaining power, and charging duration of each forklift daily to form a power usage ledger. Identify abnormally power-consuming vehicles through data analysis and conduct fault troubleshooting in advance.

4. Responsibility Assessment and Accountability

1. 1.Assessment Standards

2. The monthly under-voltage operation rate shall be 0. For each occurrence of under-voltage operation, deduct the performance scores of the corresponding operator and team leader.Equipment maintenance personnel shall ensure a 100% charging qualification rate. Those who cause battery under-voltage due to non-compliance with charging standards shall be held accountable for maintenance responsibilities.

3. 2.Training and Assessment

4. Organize special training on "winter power management and control" once a week, assess the operators' mastery of early warning thresholds and emergency handling procedures, and suspend the on-the-job qualification of those who fail the assessment.