As lithium batteries become more intelligent and connected, especially in e-mobility and industrial equipment, the role of CAN communication in lithium batteries has become increasingly important. Engineers, product managers, and buyers need batteries that can accurately exchange data with controllers, monitors, and cloud systems. Understanding how CAN works and why it has become the industry standard can help businesses make better decisions when choosing a supplier or designing a new product.
CAN communication in lithium batteries refers to the use of the Controller Area Network (CAN) protocol to exchange real-time data, such as voltage, temperature, SOC, SOH, and fault information between the battery, BMS, motor controller, and other devices. It enables safer, faster, and more reliable system-level communication in e-mobility and industrial applications.
In this guide, we’ll break down how CAN communication works inside lithium batteries, what data it delivers, why many buyers prefer CAN over RS485, and how it enhances performance in real-world applications like e-bikes, e-scooters, AGVs, robots, and energy systems. By the end, you’ll have a clear understanding of how CAN fits into modern battery architecture and what to look for when choosing a battery supplier.
What Is CAN Communication in Lithium Batteries?
The Controller Area Network (CAN) is a robust serial communication protocol that allows multiple electronic control units (ECUs) to talk to each other without a host computer. Originally developed for automotive applications, CAN has become a preferred standard for lithium battery systems because it supports high-speed, reliable, and noise-resistant data transfer across multiple nodes. Key characteristics that make it perfect for lithium batteries:
- Multi-master architecture: any device can transmit when the bus is free
- Message priority via 11-bit or 29-bit identifiers (lower ID = higher priority)
- Built-in error detection (CRC, ACK, bit stuffing)
- Differential signaling (CAN-H and CAN-L) for excellent noise immunity
- Data rates from 10 kbit/s up to 1 Mbit/s (CAN FD reaches 8 Mbit/s+)
In a lithium battery context, the BMS, charger, inverter, vehicle ECU, and display all share the same two-wire CAN bus.
How CAN Communication Works in Battery Management Systems (BMS)
Within a BMS, CAN acts as the communication backbone:
- Message Frames: Data is organized into CAN frames with specific IDs.
- Master–Slave Architecture: Often, the controller is the master, and the battery acts as a slave responding to requests.
- Real-Time Data Transmission: CAN broadcasts continuous information such as SOC, temperature, and error status.
- Multi-Device Network: Multiple devices can read the same information without conflict.
How CAN Enhances BMS Functionality
A modern lithium-ion Battery Management System must monitor hundreds of parameters in real time: cell voltages, temperatures, current, state of charge (SOC), state of health (SOH), and insulation resistance.
CAN communication in lithium batteries enables:
- Precise cell balancing commands
- Immediate fault detection and contactor control
- Dynamic charge/discharge current limits sent to chargers and motor controllers
- Remote diagnostics and over-the-air updates
- Redundant safety layers (e.g., ISO 26262 ASIL-D in EVs)
Without reliable CAN communication, a BMS would be blind to the rest of the system — leading to reduced performance or catastrophic failures.
Key Benefits of CAN Communication in Lithium Batteries
Advantage | Impact on Lithium Systems |
|---|---|
High noise immunity | Critical in high-current, high-voltage environments |
Real-time capability | Enables fast protection and dynamic power control |
Deterministic behavior | Predictable latency even under heavy bus load |
Scalability | Easily add more modules or peripherals |
Standardization | Huge ecosystem of chips, tools, and expertise |
Fault tolerance | Automatic error detection and node isolation |
Compared to simpler protocols like RS-485 or SMBus, CAN offers far superior speed and reliability when safety matters. For e-bike, e-scooter, and industrial, these benefits translate into safer and smarter systems.
CAN vs. Other Communication Protocols in Battery Systems
Protocol | Max Speed | Topology | Typical Use in Batteries | Drawbacks vs CAN |
|---|---|---|---|---|
CAN | 1 Mbps | Multi-master | EVs, large ESS, industrial packs | Slightly higher cost |
CAN FD | 8 Mbps | Multi-master | Next-gen high-power systems | Not backward compatible everywhere |
RS-485 | 10 Mbps | Master-slave | Small packs, cost-sensitive projects | No built-in priority, weaker error handling |
SMBus/I2C | 100–400 kbps | Master-slave | Laptop batteries, small modules | Very limited range and nodes |
Modbus RTU | 115 kbps | Master-slave | Some industrial systems | Not real-time, polling overhead |
For any lithium battery pack above 10–20 kWh or with safety-critical applications, CAN (or CAN FD) is usually the best choice.
CAN Protocols Commonly Used in Lithium Battery Applications
Different applications use different CAN variants:
- CAN 2.0A / CAN 2.0B: Most commonly used in e-mobility.
- CANopen: Often used in industrial equipment or AGVs.
- SAE J1939: Widely adopted for heavy-duty vehicles and machinery.
- Proprietary CAN (custom CAN): For OEMs needing specific data structures or integration formats.
Battery suppliers like Tritek often provide custom CAN mapping to match the controller’s requirements.
CAN Communication in E-Mobility Applications
In electric two-wheelers and light EVs, CAN plays a central role:
- Communicates with the motor controller for torque, speed, and power requests
- Connects to the VCU for system-level decision-making
- Works with displays/HMI to show battery status
- Supports dual-battery or parallel systems with automatic ID management
- Links to IoT modules (Bluetooth, 4G, GPS) for cloud reporting and tracking
This makes CAN essential for high-performance e-mobility products.
How Tritek Implements CAN Communication in Intelligent Lithium Batteries
Tritek integrates CAN communication deeply into its intelligent BMS architecture:
- Customizable CAN mapping for easy integration
- Real-time diagnostics and error reporting
- Full interoperability with controller, VCU, and IoT modules
- OTA and remote update capability
- Support for multi-battery and hot-swappable systems
- Stable communication with CAN 2.0B, RS485, UART, and more
With over 15 years of R&D experience and strong manufacturing capability, Tritek delivers CAN-enabled battery solutions for e-mobility, robotics, agriculture equipment, marine applications, and more.
Final Thoughts
CAN communication in lithium batteries has become the foundation of modern battery intelligence, allowing systems to operate more safely, efficiently, and intelligently. Whether you’re building an e-bike, designing a robot, or developing industrial equipment, choosing a battery with strong CAN support is critical for system performance.
