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EVs are thriving as a feasible commuting alternative to alleviate environmental problems by reducing dependence on fossil fuels. And the rising demand for EVs necessitates automotive players to consider multiple aspects influencing their effectiveness and performance, ultimately experienced by the users. This resulted in numerous research pivoted by manufacturers and OEMs focused on boosting electric vehicle (EV) performance for the upcoming decades. One such outcome is the battery management system for electric vehicles, which helps monitor battery performance and control associated parameters. Integrating a BMS in electric vehicles ensures competent and safer EV offerings.

The Global Electric Vehicle Battery Management Systems Market was 1.42 billion US$ in 2021. The market is projected to grow at a CAGR of 17.2% from 2022 to 2027, reaching US$5.67 billion by 2027.

These numbers merely cement the fact that BMS is nothing but the nerve center for electric vehicles, playing a critical role in managing the battery’s performance. This blog discusses the Battery Management System’s (BMS) significant contribution to Electric Vehicles (EVs).

Types of batteries in electric vehicles

So, when it comes to the types of batteries used in electric vehicles (EVs), the most popular ones are lithium-ion batteries. They’ve really taken the spotlight because they offer a great balance of energy density, lifespan, and weight.

Then, we have nickel-metal hydride (NiMH) batteries, which you might remember from older hybrids. They’re reliable but don’t quite match the performance of lithium-ion batteries, especially when it comes to capacity.

Lead-acid batteries are also an option, mostly found in some older or budget-friendly electric vehicles. They’re on the heavier side and not as efficient as lithium-ion, but they are cheaper, which can be a plus for some.

Now, let’s not forget about solid-state batteries! These are exciting because they’re still developing but promise higher energy density and better safety. In precise, it is a battery that’s lighter and lasts longer.

Lastly, there are ultracapacitors. Technically, they have a low energy density but a high power density, meaning they can deliver much power quickly.

There are several other types of batteries used in EVs beyond these, each offering distinct advantages, and the choice really depends on what the vehicle needs.

We’ve touched on the different types of batteries in electric vehicles. Each battery has its own strengths, but a robust management system is crucial to ensure they function efficiently and safely.

What is a Battery Management System for Electric Vehicles?

A Battery Management System, commonly known as BMS, is an electronic unit that monitors and controls the performance of EV batteries. It controls voltage, temperature, and state of charge, which are critical parameters for the safe operation of batteries in EVs.

Why do we need a Battery Management System for Electric vehicles?

As we already discussed, Lithium-ion batteries are the most favored category among the batteries used in electric vehicles, owing to high power density, low self-discharge, and reasonably low cost. Nevertheless, along with the advantages, many safety risks are involved in making an electric vehicle with a lithium battery. Because under unusual conditions, lithium-ion batteries can fail and even catch fire. For instance, this can happen due to overcharging or thermal runaway. Additionally, age and wear also contribute to these failures. Therefore, automakers and OEMs must implement effective battery management system. These systems help ensure batteries operate within safe limits. Consequently, this promotes safer e-mobility. The section below explains what and how the BMS in electric vehicles addresses battery operations.

In an electric vehicle, a battery amalgamates several modules, each a collection of individual cells. It is challenging to monitor battery pack performance since each cell in each module tends to charge and discharge at different rates. Also, each cell functions differently due to temperature, health status, and energy. Therefore, each battery cell must be independently observed for safer and more efficient operation. This is where the BMS board comes into play.

The BMS board is a physical circuit board in BMS that performs routine checks on the performance and health of battery cells. And if it detects any anomalies, it takes immediate corrective measures. This inspection ensures the battery’s safe and reliable operation, producing an efficient and safe electric vehicle for consumers.

Types of Battery Management System for Electric Vehicles

So, let’s talk about types of Battery Management System, or BMS, in electric vehicles. Manufacturers can choose from three main types: centralized BMS, Distributed BMS, and Modular BMS.

First, we have the Centralized BMS. This setup features a single controller managing all the battery cells in the system. It’s a simple and cost-effective solution, making it a popular choice for budget-friendly electric vehicles. However, the catch is that if that one controller fails, the entire system could come to a halt.

Next is the Distributed BMS. In this configuration, multiple control units are used, with each one managing a specific group of battery cells. A BMS board is installed at each cell, and a single communication cable connects them to a central controller. This design boosts reliability since if one control unit encounters an issue, the other units can continue to operate. A great example of this would be Tesla, which utilizes a distributed approach to monitoring its battery performance in real-time.

Lastly, we have the Modular BMS. This system employs several controllers, with each managing a specific number of cells. There’s communication between these controllers, which allows for easier troubleshooting and maintenance compared to a centralized system. While it can be more expensive, it offers the advantage of maintaining operations even if one controller has problems, making it a solid choice for more complex battery setups.

In summary, the choice between Centralized, Distributed, and Modular Battery Management System for electric vehicles ultimately hinges on what best fits the automaker’s goals and their customers’ needs. As they navigate the trade-offs between cost, reliability, and overall performance, each type of battery management system presents its own advantages and challenges, allowing manufacturers to tailor their approach based on their specific requirements and market demands.

Functions of Battery Management System in Electric Vehicles

The Battery Management System plays several critical functions in electric vehicles, as in the following pointers.

Cell Monitoring:

The BMS board fetches real-time data on fundamental battery parameters like voltage, temperature, and current. With these metrics, the BMS board closely monitors important performance parameters like State of Charge (SoC), denoting the amount of charge remaining out of the EV battery’s maximum capacity and State of Health (SoH), showing the overall status of battery pack health. SoC monitoring helps EV customers assess their disposable driving range and plan their charging station stops without worrying much about range anxiety. With SoH monitoring, EV manufacturers could practically assist their customers by providing heads-ups on preventive maintenance, retaining healthy battery conditions, and prolonged performance.

Thermal Management:

Electric Vehicle Batteries are sensitive to temperature variations, influencing their performance and lifespan. On this note, the Battery Management System in electric vehicles carefully regulates the thermal state of the battery through constant monitoring and control of battery temperature values to maintain optimal operation. For instance, this can involve utilizing heating-cooling mechanisms to keep the batteries within ideal temperatures to maximize their performance and lifespan.

Cell Balancing:

BMS includes a cell balancing process to ensure that the energy cells perform uniformly. Battery management systems in EVs use two methods to equalize voltage and charge among cells. First, the active balancing method transfers energy from overcharged to undercharged cells, promoting balance. Conversely, the passive balancing method discharges excess energy as heat. Ultimately, both methods prevent any cell from becoming overcharged or undercharged.

Simply put, cell balancing increases the efficiency and longevity of an electric vehicle’s battery pack.

Battery Optimization:

The Battery Management System in electric vehicles vigilantly monitors the multiple parameters of the battery packs since battery cells may lose their integrity as they naturally deteriorate over time. It has built-in protections for overvoltage, undervoltage, overcurrent, thermal management, and external overcharge/discharge incidents. In case of anomalies, the system will automatically regulate the pre-defined protection process, like optimized low-voltage charging for damaged cells and balancing voltage variations due to oxidation, to keep the battery performance optimal.

This makes the BMS an essential component as it ensures the functioning, reliability, and safety of batteries used in electric vehicles, thereby enhancing the growth of eco-friendly transport for your potential consumers.

Benefits of using a Battery Management System for Electric Vehicles:

BMS has several significant advantages for electric vehicles. These benefits include:

Performance Optimization:

BMS helps derive the maximum performance of the battery packs to extend the driving range and battery longevity through automated mechanisms to resolve anomalies and malfunctions pertaining to the battery.

Safety and Reliability:

BMS has complete monitoring and safety mechanisms for overcharging, draining, and temperature abnormalities. This ensures the safety and durability of a battery, thus minimizing accidents or failures for EV buyers.

Real-time Data and Diagnostics:

BMS observes batteries in real time, records data for logs on battery health, and identifies malfunctions. This helps OEMs schedule proactive maintenance to rectify issues and significantly enhance customer satisfaction.

Automotive OEMs consistently test new waters to evolve their BMS capabilities and strengthen their automotive offerings. Some notable developments in the BMS space include:

Intelligent BMS:

By employing advanced algorithms and machine learning techniques, BMS can optimize battery performance according to patterns of batteries’ utilization, environment conditions, and other dynamic scenarios. This advancement is valuable for automakers by reducing warranty claims and enhancing their reputation for reliability.

External Communication:

Currently, the battery management system for electric vehicles increasingly leverages wireless communication protocols. This allows for rapid system enhancements through Over-the-Air (OTA) updates. This enables system enhancements to be delivered rapidly through Over-the-Air (OTA) updates. Meanwhile, with timely updates, Automotive OEMs can ensure their BMS functionality and performance are intact.

Advanced Predictive Algorithms:

Also, Battery management system in electric vehicles increasingly integrate advanced predictive maintenance systems. These algorithms rely on real-time data to anticipate when battery components may require repair or replacement. Thus, they reduce customer maintenance costs, improve vehicle reliability, and enhance brand reputation.

As we can see, BMS capabilities are progressing by leaps and bounds with new technological innovations, and it is time for automotive OEMs to keep pace with this evolution.

SRM Technologies offers expertise in automotive embedded engineering, providing Battery Management Solutions to enhance battery performance.

Talk to us to accelerate your e-mobility initiatives and optimize battery utilization effectively.

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