Optimising Energy: Battery Management System

When it comes to manufacturing battery systems for electric vehicles, effective battery management is crucial for performance, longevity, and safety. At the heart of this management lies sophisticated software solutions designed to monitor, control, and optimise battery operation – battery management system (BMS). Here at BOLD, we develop our own BMS technology thanks to internal software and hardware teams. Read on as we delve into the vital role a BMS plays in battery optimisation.

BOLD’s Software team working on BMS coding

What is a BMS?

A BMS monitors and manages the health, performance, and lifespan of a battery, in other words, serving as the ‘brain’ controlling the system.

Here’s a breakdown of its key functions:

  • Cell Monitoring: Monitors individual cells within the battery pack for parameters such as voltage, temperature and current. This ensures that each cell operates within safe limits and prevents overcharging or over-discharging.
  • State of Charge (SoC) Estimation: Determines how much energy is left in the battery pack. Accurate SoC estimation is essential for predicting the available range in electric vehicles and ensuring proper energy management.
  • State of Health (SoH) Estimation: Assesses the overall health and degradation of the battery pack over time. By monitoring factors like capacity fade and impedance increase, the BMS can provide insights into the remaining useful life of the battery.
  • Balancing: Ensures that energy is evenly distributed among the individual cells in the pack. This prevents some cells from being overcharged while others are undercharged, which can lead to capacity imbalances and reduced pack performance.
  • Temperature Management: Monitors and regulates the temperature of the battery pack to prevent overheating or overcooling, which can degrade performance and shorten lifespan.
  • Safety Protection: Implements safeguards to prevent and detect hazardous conditions such as overvoltage, undervoltage, overcurrent, insulation faults and short circuits. In extreme cases, the BMS may disconnect the battery pack from the load to prevent damage or fire.
  • Communication: Provides interfaces for communication with external systems, such as vehicle control units or energy management systems. This allows for real-time monitoring, remote diagnostics, datalogging, and integration with other vehicle or device functions.

The BMS is crucial for orchestrating various tasks essential for their optimal functioning. By continuously assessing and regulating these parameters, BMS ensures efficient energy utilisation and prolongs battery life.

PCB which interfaces with vehicle in marine applications (LV and HV measurements)

What is the importance of an efficient BMS?

An efficient Battery Management System (BMS) is crucial for several reasons:

  • Safety: Safety is paramount when dealing with rechargeable battery packs, which can suffer overheating, overcharging, or other hazardous conditions during operation. An efficient BMS continuously monitors and manages these risks, implementing safeguards to prevent accidents such as fires or explosions.
  • Performance Optimization: A well-designed BMS can optimize the performance of the battery pack, ensuring that it operates at its maximum efficiency and delivers the required power output. This is especially important in applications like electric vehicles, where performance directly impacts factors such as acceleration, range, and overall driving experience.
  • Extended Battery Life: Proper management of charging and discharging cycles can help extend the lifespan of the battery pack. An efficient BMS monitors factors such as state of charge, state of health, and temperature, allowing for proactive measures to mitigate degradation and prolong the battery’s useful life.
  • Range Estimation: In electric vehicles and other mobile applications, accurately estimating the remaining range is essential for planning trips and avoiding unexpected disruptions. A reliable BMS provides accurate state of charge estimation, allowing drivers to make informed decisions about when and where to recharge.
  • Cost Savings: Efficient battery management can lead to cost savings over the lifetime of the battery pack. By optimizing performance and extending lifespan, an effective BMS reduces the need for premature replacements or repairs, saving money on maintenance and downtime.
  • Environmental Impact: Battery technology plays a significant role in the transition to clean energy and reducing greenhouse gas emissions. An efficient BMS maximizes the energy efficiency of battery systems, contributing to overall sustainability and environmental benefits.
  • User Experience: In consumer electronics and electric vehicles, a smooth and reliable user experience is essential for customer satisfaction. An efficient BMS ensures that the battery pack operates seamlessly, providing consistent performance and minimizing the risk of unexpected failures or disruptions.
BMS tests, against our in-house test rig to evaluate the software with our cell emulators

Our internal electronics team take these crucial steps in the process of developing BMS.

  • Requirements Analysis: The first step is to define the requirements of the BMS based on the specific application and the characteristics of the battery pack. This includes determining the number of cells to be monitored, the desired measurement accuracy, the required communication interfaces, and any safety or regulatory standards that must be met.
  • Hardware Development: Hardware development in a BMS includes designing electronic circuits, selecting components, prototyping PCBs, rigorous testing, integrating with software, and preparing for production. Emphasis is placed on safety, reliability, and performance optimization to meet specific application requirements such as electric vehicles or grid energy storage systems.
  • Firmware Development: Firmware is developed to run on the microcontroller, implementing algorithms for cell and battery monitoring, data processing, and communication. This includes libraries for measuring cell voltages, temperature, current, as well as algorithms for calculating state of charge (SoC), state of health (SoH), balancing and contactors control.
  • Testing and Validation: The BMS is subjected to rigorous testing to ensure that it meets performance specifications and reliability standards. This includes functional testing to verify sensor accuracy and communication interfaces, as well as environmental testing to assess performance under various temperature and operating conditions.
  • Integration with Batteries: Once the BMS has been validated, it is integrated into a real battery. This involves testing the overall system to ensure proper operation.
  • Certification and Compliance: Once the BMS has been tested, depending on the application, specific certifications and compliance testing is necessary to meet safety, regulatory, and industry standards. This normally includes testing for electromagnetic compatibility (EMC), electrical safety, and environmental compliance.
Bold uses laboratory equipment to validate the electronic circuits, such as power supplies, precision multimeters and oscilloscopes

This process can be exceptionally complex, and we face several challenges in developing an effective BMS. Ensuring accuracy and reliability is critical, as sensor inaccuracies, noise, and environmental factors can affect performance. This requires thorough sensor calibration, signal filtering, and extensive testing under various conditions. Safety and compliance with standards like ISO 26262 and IEC 61508 are essential, necessitating rigorous testing and documentation. Integrating the BMS with other system components, such as cell monitor units, multi-sensors, and vehicle control systems, can be complex, requiring close collaboration between engineering teams. The software’s complexity, including control algorithms and communication protocols, demands optimization and real-time responsiveness, which can be managed through modular design and rigorous testing. Cost optimization is also vital, achieved through value engineering and design for manufacturability. Finally, ensuring scalability and futureproofing involves designing flexible architectures and staying updated with industry trends.

Electronics team checking the design of a PCB in Altium design software.

Developing our own BMS can greatly benefit our customers. Tailoring the BMS to specific product and application needs enables unique offerings with standout features, enhancing market appeal and providing customers with tailored solutions, improving performance and reliability. Custom-designed BMSs offer optimised algorithms, advanced safety features, and compatibility, ensuring products meet customer expectations for performance, longevity, and safety. With an in-depth understanding of the BMS architecture and HW and SW design, troubleshooting becomes faster and more efficient. Additionally, custom implementations are streamlined, allowing for quicker response to customer needs and market demands. With our team taking responsibility for ongoing support, maintenance, and updates, our customers will receive continuous assistance, firmware upgrades, and prompt issue resolution throughout the product lifecycle.

Quality inspection (visual and functional testing) in our marine application BMS

In summary, an efficient BMS is crucial for enhancing safety and performance, whilst reducing risks. By preventing overcharging, over-discharging, and overheating, BMS reduces the risk of battery failure and associated safety hazards. It enhances the overall user experience and lowers maintenance costs, resulting in tangible benefits for our customers. We’re committed to developing superior BMS that meets customer needs and secures BOLD a competitive edge in the market.

If you’d like to learn more about our battery systems and the development of our BMS, please reach out to a member of our team at sales@boldvaluable.tech.

Electronics team checking the design of a PCB in Altium design software.

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