Introduction
A Battery Management System (BMS) is a system that monitors and manages a battery pack to ensure it operates safely, efficiently, and reliably, making it a critical component in electric vehicles. Its main functions include measuring voltages, currents, and temperatures and balancing the cells to maintain consistent performance.
This overview introduces a series on the architecture, development and integration of a battery management system developed using NXP hardware and software. To accelerate this process, MathWorks ecosystem is used to streamline the development, maintain traceability from model to implementation and to validate complex embedded applications.
Overview
Articles roadmap
Developing a battery management system is a complex undertaking, and explaining it thoroughly requires a structured series of articles. Each article focuses on a key stage of the development process, offering detailed insight into how such a system is designed, implemented, tested, and validated from concept to deployment.
The series includes the following articles:
- Software and Hardware Environment - An overview of the required software environment, including NXP software development kits (SDKs), real-time drivers (RTDs), and MathWorks toolboxes, together with the hardware platform used in the application.
- Architecture and Model Description - A detailed description of the system architecture, including the model structure, input and output signals, and the core algorithms used in the battery management system.
- Validate the BMS Algorithms (Model-in-the-Loop) - An explanation of how validated MathWorks battery management assets - such as state-of-charge (SoC) and state-of-health (SoH) estimation algorithms - can be adapted, integrated, and verified within the application model.
- Preparing BMS Algorithms for Code Generation (Software-in-the-Loop) - Guidance on generating production-oriented code from validated models and running software-in-the-loop (SiL) simulations to compare code behavior against the model-in-the-loop (MiL) baseline.
- Bringing the BMS Closer to Hardware (Processor-in-the-Loop) - Steps to prepare the model for execution on target hardware by deploying the generated software to an NXP evaluation board while emulating battery measurements on a host PC.
- Deployment and Validation on the High-Voltage BMS Reference Design Kit - Configuration of external devices to supply real data to the BMS algorithms, followed by system-level validation.
- Extending the Controller with CAN Communication - Integration of controller area network (CAN) communication by defining the CAN database, configuring the communication stack, and validating message exchange on the NXP hardware.
- Final Results - A summary and discussion of results, along with final validation of the complete battery management system.
What is the Battery Management System?
A Battery Management System (BMS) is a combined hardware and software system responsible for monitoring, controlling, and protecting an electric vehicle's battery pack. Technically, it acts as the central authority that has full visibility into the battery's operating conditions, such as cell voltages, pack current, and temperatures. Based on this information, the BMS makes real-time decisions to keep the battery within safe operating limits. It also enforces critical protections - such as preventing overcharge, over-discharge, over-temperature, or short-circuit conditions - which are essential for safety, reliability, and regulatory compliance.
From a functional perspective, the BMS performs several key jobs that directly impact vehicle performance and longevity. These include estimating battery states such as State of Charge (SoC), State of Health (SoH), and available power, which higher-level vehicle systems rely on for range prediction and energy management. The BMS also manages cell balancing, ensuring that individual cells within the pack age uniformly and maintain similar voltage levels. This combination of accurate state estimation and active control helps maximize usable energy, protect the battery from accelerated degradation, and maintain consistent performance throughout the vehicle's life.
On the hardware side, a BMS typically consists of sensing components (voltage, current, and temperature sensors), cell monitoring and balancing ICs, a microcontroller, isolation components, and communication interfaces. These elements work together to acquire high-precision measurement data from the battery pack and execute control actions such as enabling contactors or activating balancing circuits. In many architectures, the system is distributed, with multiple cell monitoring units communicating with a central BMS controller.
The software layer ties everything together and is often the most complex part of the system. BMS software includes low-level drivers for sensors and communication, real-time control logic, diagnostic and fault-handling mechanisms, and advanced algorithms for state of charge estimation. It must integrate seamlessly with the rest of the vehicle through networks such as CAN, allowing the BMS to exchange data with vehicle control units, chargers, thermal management systems, and the powertrain. Through this tight hardware-software integration, the BMS becomes a core enabler of safe operation, efficient energy use, and coordinated vehicle behavior.
Target Audience
This article series is intended for engineers, technical specialists, and decision-makers involved in the development, integration, or evaluation of high-voltage battery management systems for electric vehicle applications. It is especially relevant for readers who want to understand how BMS algorithms, embedded software, hardware platforms, and validation workflows come together in a complete development process. The content is suitable for both engineers looking for practical implementation guidance and technical stakeholders interested in the benefits of using a Model-Based Design approach with MathWorks and NXP solutions.
The main target audience includes:
- Embedded software engineers
- Control and algorithm engineers
- Battery system engineers
- Electric vehicle system architects
- Model-Based Design engineers
- Hardware and integration engineers
- Test and validation engineers
- Technical managers and project leads
Context
In the electric vehicle architecture presented in this series, the Battery Management System is located in the rear zone of the vehicle. It is a safety-critical controller responsible for battery supervision, but it operates within a highly interconnected ecosystem. It bridges:
- Battery pack (physical layer)
- Vehicle Control Network (communication layer)
- Powertrain and Vehicle Behavior (functional layer)
The HVBMS is implemented on the reference design bundle for 800 V high-voltage battery management systems. It provides a complete hardware solution including:
- RD-K358BMU - battery management Unit (BMU)
- RD33774CNT3EVB - cell monitoring unit (CMU)
- RD772BJBTPL8EV - battery junction box (BJB)
- 18 Cell Battery Pack Emulator
References
Conclusion
This article introduced the Battery Management System within the context of an electric vehicle architecture and established the technical foundation for the rest of the series. It described the role of the Battery Management System and illustrated how a Model-Based Design workflow can be implemented by combining the MathWorks and NXP ecosystems.
The next article will focus on the software and hardware environment needed to develop, simulate, and deploy a Battery Management System using MathWorks and NXP solutions.