How to Specify a Cold Storage AGV Battery for Low-Temperature Duty

Cold storage AGVs operate under conditions that place specific requirements on lithium battery packs. Low temperatures can affect battery capacity, internal resistance, charging performance, voltage stability, and BMS protection. AGVs may also move between freezer areas, loading zones, and ambient-temperature environments, creating repeated temperature transitions.

For OEMs, AGV manufacturers, warehouse automation companies, and system integrators, battery selection should consider the complete operating profile rather than voltage and capacity alone.

A cold storage AGV battery specification should address cell chemistry, voltage, capacity, current, low-temperature charging, battery heating, BMS, enclosure protection, communication, and mechanical integration.

1. Define the AGV Operating Temperature

The first step is to identify the actual temperature conditions.

A battery specification should include:

• Normal operating temperature

• Minimum ambient temperature

• Maximum ambient temperature

• Cold-soak duration

• Charging temperature

• 
  

• Temperature transition frequency

• Operating hours per shift

• Charging location

For example, an AGV may operate at -20°C for several hours and then return to a 10°C loading area for charging.

This is different from an AGV that only enters a freezer for a few minutes.

Cold-soak duration is important because battery cell temperature changes gradually in response to the surrounding environment. A battery exposed to -20°C for several hours has different electrical characteristics from a battery that briefly passes through a freezer.

The battery supplier should evaluate the cell and pack according to the actual temperature profile.

2. Understand Low-Temperature Battery Performance

Lithium-ion battery performance changes as temperature decreases.

Low temperature can result in:

• Increased internal resistance

• Reduced available capacity

• Greater voltage drop under load

• Reduced charging capability

• Increased risk of low-voltage protection during high-current operation

These effects can occur when an AGV accelerates, climbs a ramp, lifts a load, or operates at low state of charge.

Battery capacity should therefore be evaluated using temperature-specific test data.

The basic energy calculation is:

Battery Energy (kWh) = Voltage (V) × Capacity (Ah) ÷ 1,000

For example, a 48V 100Ah battery has a nominal energy value of 4.8 kWh.

However, 4.8 kWh should not automatically be treated as usable energy at -20°C. Actual available energy depends on the cell, discharge current, temperature, SOC range, BMS limits, and battery design.

For an OEM project, request discharge curves at the expected operating temperature.

3. Select the Appropriate Battery Chemistry

LiFePO4

LiFePO4 batteries are widely used in industrial applications where cycle performance, safety characteristics, and stable operation are required.

For cold-storage AGVs, an LFP battery can be designed with:

• Integrated heating

• Smart BMS

• Temperature monitoring

• CAN communication

• Custom enclosure

• Low-temperature charging protection

LFP batteries have charging limitations at low temperatures. The selected cell's charging specifications should therefore be reviewed before pack design.

NMC

NMC cells can be considered where energy density, battery weight, or available installation space is an important design factor.

LTO

LTO technology can be considered for applications involving frequent charging, high power demand, and specific low-temperature requirements.

The final chemistry should be selected according to the AGV duty cycle, temperature, available space, weight limit, charging strategy, and required battery life.