Logistics Robot Battery | Custom Lithium Battery Pack

Electric tow tractors are used to move carts, trailers, material racks, and other loads in warehouses, factories, airports, distribution centers, and industrial facilities.

The battery supplies electrical energy to the traction motor, motor controller, steering system, display, safety equipment, and other electrical components.

A lithium battery for electric tow tractors needs to match the electrical and mechanical requirements of the vehicle. Voltage and capacity are important parameters, while battery current, towing load, operating cycle, charging method, installation dimensions, BMS configuration, and environmental conditions also need to be considered.

A custom lithium battery pack can be developed according to the specifications of the electric tow tractor.

What Is an Electric Tow Tractor Battery?

An electric tow tractor battery is a rechargeable battery pack that supplies electrical power to an electric towing vehicle.

Depending on the vehicle design, the battery may provide power to:

• Traction motors

• Motor controllers

• Steering systems

• Hydraulic systems

• Braking systems

• Displays

• Lighting

• Safety systems

• Communication equipment

The required battery configuration depends on the vehicle's electrical architecture and operating requirements.

Why Use Lithium Batteries for Electric Tow Tractors?

Lithium-ion batteries can be used in electric tow tractor applications where rechargeable energy storage is required.

Battery selection can consider:

• Voltage

• Capacity

• Energy

• Continuous current

• Peak current

• Charging requirements

• Battery dimensions

• Battery weight

• BMS functions

• Operating temperature

LiFePO4 is one lithium-ion chemistry that can be evaluated for industrial tow tractor applications. The appropriate chemistry depends on the equipment requirements and operating conditions.

LiFePO4 Battery for Electric Tow Tractors

LiFePO4, also known as lithium iron phosphate or LFP, is a lithium-ion battery chemistry used in rechargeable battery systems.

For example, a 51.2V 100Ah battery has a nominal energy of:

51.2V × 100Ah = 5,120Wh = 5.12kWh

Actual usable energy depends on the battery operating window, load, temperature, BMS settings, and system efficiency.

When selecting a LiFePO4 battery for an electric tow tractor, the engineering team should also evaluate current requirements, operating cycles, charging conditions, installation space, and vehicle control requirements.

How to Calculate Battery Capacity

The basic formula is:

Battery Energy (Wh) = Voltage (V) × Capacity (Ah)

For example:

48V × 100Ah = 4,800Wh

Estimated operating time can be calculated using:

Operating Time = Available Energy ÷ Average Power Consumption

Actual operating time depends on:

• Towing load

• Driving speed

• Acceleration

• Travel distance

• Motor efficiency

• Operating surface

• Operating cycle

• Temperature

• Auxiliary electrical loads

For an OEM project, battery capacity should be determined from the vehicle's actual operating profile.

Towing Load and Battery Current

Towing load affects the motor power and battery current requirements.

When the vehicle starts, accelerates, pulls a heavy load, or operates on a ramp, current may increase.

Battery design should therefore consider:

Continuous Current

The current required during normal operation.

Peak Current

Short-duration current associated with startup, acceleration, heavy towing, or other load changes.

The battery cells and BMS should be selected according to these requirements.

Other components should also be evaluated, including:

• Fuse

• Busbars

• Cables

• Connectors

• Motor controller

• BMS

Smart BMS for Electric Tow Tractor Batteries

A Battery Management System, or BMS, monitors and protects the battery pack.

Depending on the configuration, the BMS can monitor:

• Cell voltage

• Battery voltage

• Charging current

• Discharging current

• Temperature

• SOC

• SOH

Protection functions may include:

• Overcharge protection

• Over-discharge protection

• Over-current protection

• Short-circuit protection

• Over-temperature protection

• Under-temperature protection

Cell balancing can also be included according to the battery design.

BMS parameters should correspond to the battery cells, battery configuration, current requirements, and charger specifications.

CAN Communication for Tow Tractor Batteries

Some electric tow tractors require communication between the battery and vehicle controller.

CAN communication can transmit information such as:

• Battery voltage

• Current

• SOC

• Temperature

• Charging status

• Fault status

For OEM battery projects, the BMS can be configured according to the vehicle communication protocol.

Required information may include:

• CAN ID

• Baud rate

• Data format

• Communication commands

• Fault codes

• SOC format

Communication should be tested with the vehicle controller during prototype validation.

Other interfaces, such as RS485 or UART, can also be considered according to the vehicle control system.

Charging Solutions

The charger should be compatible with the battery configuration.

Important charging parameters include:

• Battery chemistry

• Charging voltage

• Charging current

• Charger power

• Charging connector

• Charging time

• BMS requirements

• Communication requirements

Electric tow tractors may use standard charging, opportunity charging, or automated charging.

The battery and charger should be evaluated as a complete system.

Custom Battery Dimensions

Battery compartments vary between tow tractor models.

A custom battery pack can be designed according to:

• Length

• Width

• Height

• Mounting points

• Connector position

• Cable outlet

• Enclosure structure

Customers can provide:

• 2D drawings

• 3D models

• Battery compartment drawings

• Connector specifications

• Mounting requirements

These specifications can be used for battery enclosure and internal configuration design.

Battery Enclosure and Environmental Requirements

The battery enclosure protects cells, BMS components, wiring, and other electrical parts.

Potential enclosure materials include:

• Aluminum

• Steel

• ABS

• PC

• Engineering plastics

The design may address:

• Mechanical protection

• Heat dissipation

• Dust protection

• Water protection

• Mounting

• Connector placement

• Cable routing

Electric tow tractors may operate in warehouses, factories, airports, distribution centers, loading areas, and cold storage facilities.

The battery specification should define the required operating and charging temperature ranges.

If the equipment is exposed to dust or water, the enclosure and applicable IP protection level can be evaluated.

Lithium Battery Testing

Battery testing should be defined according to the battery design and application.

Capacity Testing

Capacity testing verifies battery capacity under specified charging and discharging conditions.

BMS Testing

BMS testing may evaluate:

• Overcharge protection

• Over-discharge protection

• Over-current protection

• Short-circuit protection

• Temperature protection

• Cell balancing

Communication Testing

For smart battery packs:

• CAN

• RS485

• UART

• SOC data

• Fault reporting

• Charging status

Temperature Testing

Testing may include:

• High-temperature operation

• Low-temperature operation

• Charging temperature

• Temperature monitoring

Mechanical Testing

Depending on the application:

• Vibration

• Impact

• Connector

• Mounting

• Enclosure

Certifications for Electric Tow Tractor Batteries

Certification requirements depend on the battery configuration, application, transportation method, and target market.

For lithium battery transportation, UN 38.3 is an important transportation testing requirement.

Depending on the product and destination market, additional requirements may include:

• CE

• IEC standards

• UL standards

• RoHS

• EMC requirements

• Regional battery regulations

For products placed on the European market, applicable requirements under EU Battery Regulation (EU) 2023/1542 should also be evaluated.

Certification requirements should be identified during product development.

Custom Electric Tow Tractor Battery Development Process

A custom battery project can follow these steps:

1. Equipment Analysis

Collect:

• Vehicle model

• Nominal voltage

• Motor power

• Average current

• Peak current

• Towing load

• Operating time

• Charging requirements

• Battery dimensions

• Communication requirements

2. Operating Profile

Evaluate:

• Daily operating hours

• Operating cycles

• Towing load

• Travel distance

• Driving speed

• Ramp operation

• Charging frequency

3. Cell Selection

Evaluate:

• Chemistry

• Capacity

• Current capability

• Internal resistance

• Dimensions

• Temperature specifications

4. Battery Configuration

Determine:

• Series connection

• Parallel connection

• Nominal voltage

• Capacity

• Energy

• Current capability

5. BMS and Mechanical Design

Define:

• Protection parameters

• Current rating

• Temperature sensors

• SOC/SOH

• CAN/RS485/UART

• Enclosure

• Mounting

• Connectors

• Wiring

6. Prototype and Validation

Test:

• Installation

• Charging

• Discharging

• Communication

• Operating time

• Temperature

• Mechanical integration

7. Production

After prototype validation, the battery can enter production with defined quality control and inspection procedures.

OEM and ODM Tow Tractor Battery Pack

A custom battery pack can be developed according to the customer's vehicle.

Electrical Customization

• Voltage

• Capacity

• Cell configuration

• Continuous current

• Peak current

• Battery chemistry

BMS Customization

• Protection parameters

• SOC

• SOH

• CAN

• RS485

• UART

Mechanical Customization

• Dimensions

• Enclosure

• Mounting

• Connector

• Cable

• Wiring harness

Charging Customization

• Charging voltage

• Charging current

• Charger compatibility

• Charging communication

Information Required for a Custom Battery

Vehicle, motor, controller, charger, and battery compartment specifications can help with battery development.