Determination of Whether Electric Forklift Batteries Need Charging
To determine whether an electric forklift battery needs charging, a comprehensive judgment shall be made based on four dimensions: battery type (lead-acid / lithium-ion), power display, application scenario (especially low-temperature environment in winter), and abnormal signs. The specific standards and operation methods are as follows:
I. Direct Judgment Based on Power Display (Core Basis)
General Power Threshold Standards
| Scenario | Lead-Acid Battery | Lithium-Ion Battery | Operation Requirements |
|---|
Before daily operation startup | Initial power ≥ 80% (winter); ≥ 70% (summer) | Initial power ≥ 80% (winter); ≥ 75% (summer) | Prohibit operation if below the threshold and charge immediately |
Early warning during operation | Remaining power ≤ 30% | Remaining power ≤ 30% (BMS low-temperature protection threshold) | Stop operation immediately, return to the charging area, and strictly prohibit "forced use" |
Long-term storage (> 2 days) | Maintain storage power at 70%-80%; recharge if below 70% | Maintain storage power at 80%-90%; recharge if below 70% | Storage environment temperature: 5℃-20℃; avoid power deficit at low temperatures |
Power Reading Methods
- 1.Dashboard pointer / digital display: Directly read the percentage of remaining power. Note that low temperatures in winter may cause the pointer to show a "false high" reading; it is more accurate to read after standing for 10 minutes.
- 2.BMS (Battery Management System) (mainly for lithium-ion batteries): Check the real-time power, voltage, and temperature data reported by the system. If the system prompts "low power" or "charging recommended", perform the charging operation directly.
II. Supplementary Judgment Combined with Environment and Working Conditions (Key Focus in Winter)
Low temperatures in winter will cause reduced battery capacity and accelerated power consumption, requiring additional charging judgment conditions:
- 1.When the operating environment temperature is **< 5℃**, if the power consumption rate is more than 30% faster than usual, charging shall be conducted in advance even if the remaining power is > 30%.
- 2.When the ambient temperature is < -10℃, if the forklift needs to operate outdoors, the single operation time shall not exceed 1 hour, and supplementary charging shall be performed immediately after returning to avoid sudden power drop at low temperatures.
- 3.If the task volume increases temporarily (e.g., more than 20% beyond the plan), even if the current power is ≥ 40%, the task shall be split and charging shall be conducted midway to prevent deep discharge.
III. Emergency Judgment Based on Abnormal Signs (When No Power Display is Available)
If the dashboard malfunctions or there is no power display, it can be judged that the battery needs charging through the following abnormal phenomena:
- 1.Power attenuation: The forklift has weak acceleration, significantly slower climbing speed, or even "no response when the accelerator is pressed", indicating that the battery voltage has dropped sharply.
- 2.Abnormal lights / instruments: Dim dashboard lights and flashing alarm indicators (e.g., undervoltage alarm) are direct signals of battery power deficit.
- 3.Abnormal noise or odor: When a lead-acid battery is severely underpowered, there may be a slight "sizzling" sound caused by internal plate sulfation; if accompanied by an acid mist odor, stop the machine immediately for charging and check the battery status.
- 4.Frequent start-stop failures: Difficulty in starting the forklift or instantaneous power failure during start-stop indicates that the battery can no longer provide stable current and must be charged.
IV. Special Charging Precautions for Different Battery Types
Lead-Acid Batteries
- 1.It is strictly prohibited to charge only after the power is completely exhausted. The remaining 30% power is the charging critical value; over-discharge will cause plate sulfation and irreversible damage to the battery.
- 2.Charging in winter must meet the conditions of "charging room temperature 10℃-25℃ + 1-hour floating charge"; otherwise, the charging efficiency is low and the battery is easily damaged.
Lithium-Ion Batteries
- 1.Rely on the low-temperature protection function of the BMS; charging is prohibited when the temperature is < 0℃, and the battery shall be moved to a warm environment before operation.
- 2.If the BMS prompts "over-discharge protection", it indicates that the battery has been deeply underpowered. A special charger must be used for repair charging; forced charging with an ordinary charger is not allowed.
