To determine whether the battery endurance of an electric forklift meets the requirements, the core is to quantify the actual daily energy consumption demand, accurately match it with the actual outputable power of the battery, and reserve a safety margin at the same time. Below is a step-by-step practical method:
1. Step 1: Collect Core Data on Actual Daily Operating Energy Consumption
To verify if the endurance is sufficient, first calculate the daily power consumption of the forklift. Three categories of key operating parameters need to be collected:Operating Duration and Working Condition Proportion
Record the total daily operating time and the proportion of different working conditions:- No-load travel: Highest proportion with low energy consumption (e.g., transfer within workshops)
- Full-load travel: Medium energy consumption (e.g., round trips for goods handling)
- Full-load lifting/lowering: Highest energy consumption (e.g., stacking, loading and unloading)
- Standby/idle: Low energy consumption, but prolonged standby will also consume power
Energy Consumption per Unit Working Condition
The energy consumption of electric forklifts is usually measured in kWh/working cycle or Ah/h (Ampere-hour per hour), which can be obtained in two ways:- Manufacturer data: Check the equipment manual. Manufacturers provide the unit energy consumption under different working conditions (e.g., 0.12 kWh power consumption per 1km of full-load travel)
- Measured data: Use a battery power detector to record the power consumption of 1 hour of no-load/full-load travel and 100 times of full-load lifting; taking the average value is more accurate
Additional Energy Consumption Losses
Non-operating power losses must be considered to avoid underestimating the demand:- Low-temperature loss: Lithium batteries experience approximately 30% capacity degradation at -20℃, while lead-acid batteries degrade by about 50%
- Charging efficiency loss: The charging efficiency of lead-acid batteries is about 80%, and that of lithium batteries is about 95%
- Equipment aging loss: Battery capacity will degrade by 10%-20% after 1 year of use
2. Step 2: Calculate the Effective Actual Outputable Power of the Battery
The nominal battery capacity ≠ actual usable capacity; corrections need to be made based on actual working conditions:Conversion of Nominal Battery Capacity
Rated battery capacity (Ah) × Rated voltage (V) = Nominal total power (Wh), which is then converted to kWh (1 kWh = 1000 Wh)Example: For a 48V/500Ah lithium battery, the nominal total power = 48 × 500 = 24000 Wh = 24 kWhCorrection to Actual Usable Capacity
Actual usable capacity = Nominal total power × Depth of discharge coefficient × Working condition correction coefficient- Depth of discharge coefficient: To protect the battery, the maximum recommended depth of discharge for lead-acid batteries is ≤ 80% (deep discharge will shorten service life), and ≤ 90% for lithium batteries
- Working condition correction coefficient: Take 0.7-0.9 under low-temperature/heavy-load conditions, and 0.9-1.0 under normal-temperature/light-load conditions
3. Step 3: Compare Energy Consumption Demand with Effective Capacity to Determine Compliance
Calculate Total Daily Energy Consumption Demand
Total daily energy consumption = Sum of (duration of each working condition × unit energy consumption) × Loss coefficient (1.1-1.2, reserving a 10%-20% safety margin)Example: A forklift operates 8 hours a day, with a calculated basic energy consumption of 12 kWh. After adding a 15% margin, the total demand = 12 × 1.15 = 13.8 kWhEndurance Matching Judgment Criteria
- If actual usable battery capacity ≥ total daily energy consumption demand → Endurance meets the requirements
- If actual usable battery capacity ＜ total daily energy consumption demand → Insufficient endurance; the plan needs to be adjusted
4. Adjustment Plans for Insufficient Endurance
Short-term Optimization
- Increase charging frequency: Use lunch breaks and shift handovers for fast charging (lithium batteries support fast charging, reaching 80% charge in 1 hour)
- Optimize operating procedures: Reduce invalid no-load travel, avoid frequent rapid acceleration/braking
- Adjust load: Reduce the weight of single handling and decrease the number of full-load lifting operations
Long-term Solutions
- ｒｅｐｌａｃｅ with a higher-capacity battery: For example, upgrading from 500Ah to 600Ah directly improves endurance
- ｒｅｐｌａｃｅ battery type: Switching from lead-acid batteries to lithium batteries results in higher actual usable capacity for the same nominal capacity, along with better low-temperature performance
- Add a backup battery: Dual-battery rotation is suitable for high-intensity multi-shift operations
