Special Maintenance of Electric Forklift Batteries in Low-Temperature Environments

The core objectives are to prevent capacity degradation, avoid irreversible damage, and extend battery service life. Differentiated and quantifiable maintenance standards shall be formulated based on the distinct characteristics of lead-acid batteries and lithium batteries. Specific requirements are as follows:

I. General Basic Maintenance (Applicable to All Battery Types)

Storage Environment Control

Maintenance Requirements	Quantitative Standards	Frequency of Implementation
Priority storage in warm warehouses	Warm warehouse temperature maintained at 5–25℃, minimum temperature not lower than 0℃	Long-term implementation
Protection for outdoor storage	Install insulation covers (thermal conductivity ≤ 0.04W/(m·K)) and cover battery surfaces with thermal insulation layers	Immediately before storage
Avoid temperature shock	When moving batteries from low-temperature environments to warm warehouses, let them stand for 2–4 hours before operation; immediate charging is prohibited	After each transfer

Appearance and Connection Inspection

1. Clean ice, snow, and condensation on battery surfaces before daily operation to ensure no water accumulation or corrosion.
2. Check the tightness of terminal posts with torque conforming to vehicle model standards (usually 10–15N·m). Apply conductive paste or petroleum jelly to connectors to prevent oxidation.
3. Inspect battery casings and cover plates for cracks, and terminal posts for looseness or leakage. Stop using the battery immediately if damage is found.

Power Management Principles

1. Prohibit storage in undercharged state: Fully charge the battery after daily operation; residual power shall not be lower than 70%.
2. Maintenance during long-term storage: If the battery is not used for more than 7 days, perform supplementary charging once a week to maintain power at 70%–80%, and turn off the main power switch at the same time.
3. Avoid deep discharge: In low temperatures, single discharge capacity shall not exceed 60% of the rated capacity to prevent plate sulfation (for lead-acid batteries) or lithium plating (for lithium batteries).

II. Special Maintenance for Lead-Acid Batteries

Lead-acid batteries are more sensitive to low temperatures, requiring focused attention on electrolyte conditions. Specific requirements are as follows:

Electrolyte Inspection and Adjustment

1. Check electrolyte level weekly; it shall be 10–15mm above the plates. Add distilled water if insufficient (tap water or electrolyte is prohibited).
2. Charging or heating frozen electrolyte is strictly forbidden. Move the battery to an environment above 5℃ for natural thawing. After thawing, check the electrolyte level and density; adjust by adding liquid if density is abnormal.
3. Electrolyte density standard: Adjust to 1.28–1.30g/cm³ in winter (slightly higher than normal temperature to improve freeze resistance).

Special Charging Requirements

1. Charging environment temperature must be ≥ 5℃, with an ideal range of 10–25℃.
2. Adopt low-temperature adaptive charging curves; increase charging voltage by 5%–8% compared with normal temperature to avoid undercharging.
3. Perform floating charge for 30–60 minutes after full charging to ensure balanced cell voltage; fast charging mode is prohibited.

Plate Protection Measures

1. Avoid high-current discharge in low temperatures (e.g., frequent sudden acceleration, heavy-load climbing) to prevent shedding of active substances on plates.
2. If battery capacity drops sharply (below 50% of the rated value), perform equalizing charging or activation treatment; replace the battery if ineffective.

III. Special Maintenance for Lithium Batteries

Lithium batteries rely on Battery Management System (BMS) protection, so maintenance focuses on ensuring normal BMS functionality. Specific requirements are as follows:

Activation of BMS Low-Temperature Functions

1. Check BMS version before winter; upgrade to firmware supporting low-temperature protection, and enable low-temperature preheating and current-limited charging functions.
2. Monitor BMS parameters during charging: reduce charging current to 60%–80% of normal temperature level; automatically stop fast charging when battery temperature is below 0℃.
3. Pay attention to BMS alarms during operation; stop the machine immediately for troubleshooting if "low-temperature protection" or "excessive cell voltage difference" alerts appear.

Charging Operation Specifications

1. Charging in environments below -10℃ is prohibited, as it may cause lithium plating and internal short circuits.
2. Some vehicle models are equipped with battery preheating functions; activate preheating before charging, and start charging only after battery temperature rises above 5℃.
3. Avoid power interruption during charging to prevent cell voltage imbalance.

Cell Status Monitoring

1. Read cell voltage difference via BMS monthly; the voltage difference between single cells shall be ≤ 50mV. Contact the manufacturer for equalization treatment if the limit is exceeded.
2. Inspect battery pack heat dissipation channels for blockages to ensure a balance between heat dissipation and insulation in low temperatures, preventing local overheating or overcooling.

IV. Taboos for Winter Battery Maintenance

1. Never directly heat batteries with open flames or electric stoves (risk of explosion and fire).
2. Never mix batteries of different brands, capacities, or aging degrees.
3. Never continue using or charging batteries with frozen electrolyte or damaged casings.
4. Never add sulfuric acid solution to lead-acid batteries; never disassemble lithium battery packs.