BATTERY MANAGEMENT SYSTEM EXPLAINED WITH THE HELP OF THREE PRESENTATIONS AND 65 VIDEOS FROM NPTL-NOC-IITM & OTHERS

BATTERY MANAGEMENT SYSTEM EXPLAINED WITH THE HELP OF THREE PRESENTATIONS AND 65 VIDEOS FROM NPTL-NOC-IITM & OTHERS

Electric vehicles (EVs) are vehicles that use electric motors instead of internal combustion engines for vehicle propulsion. EVs are powered by rechargeable batteries, which store electrical energy and provide it to the motor. These batteries are paired up with a battery management system for electric vehicle.

Typically, the battery used in EVs is some variant of the LITHIUM ION BATTERY TECHNOLOGY. which offers high energy density, long cycle life, and fast charging. However, lithium-ion batteries also face some challenges in effective operation in an EV, given the dynamic environment and intense energy demands of EVs.?

Electric Vehicle batteries consequently use a sophisticated electronic circuitry called a battery management system (BMS), which typically monitors and controls the performance and safety of the battery pack. This edition of Battery Decoded explores the various aspects of BMS, its components, functions, safety features, update capabilities, hardware specifications, role in fleet management, manufacturers, and its contribution to battery data analysis and research.

Components and Structure of Battery Management Systems

A Battery Management System for electric vehicle typically comprises three main components: a control unit, sensors, and actuators. The control unit is the brain of the BMS, which communicates with the vehicle’s main computer and other components, such as the charger, the motor, and the thermal management system. The control unit also executes the BMS algorithms, which determine the optimal operating conditions and actions for the battery. The sensors are the eyes and ears of the Battery Management System for electric vehicle, which measure various parameters, such as voltage, current, and temperature, of each cell or module in the battery pack.?

The sensors also detect faults or abnormalities in the battery, such as short circuits, overvoltage, or overtemperature. The actuators are the hands and feet of the Battery Management System for electric vehicle, which perform actions to regulate the battery’s performance, such as balancing the cells, disconnecting the battery, or cooling the battery.

The Battery Management System for electric vehicle can have different structures, depending on how the sensors and actuators are distributed and connected. The most common types of BMS structures are centralized, distributed, and modular.?

Common Types of Battery Management Systems

  • In a Centralized BMS, the sensors and actuators are connected to a single control unit, which is located near the battery pack. This structure is simple and cost-effective, but it has limitations in terms of scalability, reliability, and wiring complexity.?

  • In a Distributed BMS, the sensors and actuators are integrated into each cell or module, and each unit has its own control unit, which communicates with a master control unit. This structure is scalable and reliable, but it is more expensive and complex.

?In a Modular BMS, the sensors and actuators are grouped into modules, and each module has its own control unit, which communicates with a master control unit. This structure is a compromise between the centralized and distributed structures, offering a balance of cost, complexity, and performance.

Roles of Battery Management Systems in Lithium-ion Batteries

Most lithium-ion batteries used in EVs are equipped with a BMS, due to the inherent risks associated with overcharging, over-discharging, overheating, or damage. The Battery Management System for electric vehicle protects the battery from various hazards by limiting the charging and discharging currents, maintaining the optimal temperature range, and balancing the cells to prevent uneven degradation. The Battery Management System for electric vehicle also optimizes energy utilization and prolongs the battery life by preventing excessive cycling and deep discharging.

For example, according to a study by the National Renewable Energy Laboratory (NREL), a Battery Management System for electric vehicle can improve the energy efficiency of an EV, by reducing the energy losses and increasing the usable energy of the battery. Another study by the Argonne National Laboratory (ANL) estimated that a BMS can extend the battery life by preventing capacity fade and power fade of the battery.?

Furthermore, a report by the National Highway Traffic Safety Administration (NHTSA) revealed that a Battery Management System for electric vehicle can prevent or mitigate 99.8% of the potential incidents of battery fires or explosions, by detecting and isolating the faulty cells or modules.

Many companies across a small variety of industries make BMS for electric vehicles. Some of them also make battery cells or modules, while others specialize in BMS hardware or software. These companies often provide comprehensive solutions, including battery design, integration, testing, and management.?

LOHUM as a battery recycling and battery reuse company also pairs battery solutions with our Battery Management Systems developed in-house, for both stationary Energy Storage Systems and Electric Vehicle batteries, specializing in maximise battery residual value.?

How Electric Vehicles Utilize BMS?

The Battery Management System for electric vehicle facilitates the energy flow between the battery and the vehicle’s systems. It ensures that the battery delivers sufficient power and torque to the motor and that the battery receives the correct amount of charge from the charger or regenerative braking. The BMS also monitors the state of charge (SOC), state of health (SOH), and state of power (SOP) of the battery, which indicate the amount of energy, capacity, and power available in the battery, respectively. The Battery Management System for electric vehicle uses these parameters to estimate the range, performance, and lifetime of the EV.

The functionality of BMS with electric vehicles can be demonstrated by some examples. For instance, when the EV is accelerating or climbing a hill, the BMS increases the power output of the battery to meet the demand of the motor. When the EV is braking or descending a hill, the BMS reduces the power output of the battery and enables regenerative braking, which converts the kinetic energy of the vehicle into electrical energy and stores it in the battery.?

When the EV is plugged into a charger, the Battery Management System for electric vehicle regulates the charging current and voltage to ensure the optimal and safe charging of the battery. When the EV is parked or idle, the BMS minimizes the self-discharge and parasitic loads of the battery and maintains the battery temperature within the desired range.

The Role of Battery Management System in Safety

The BMS plays a vital role in Lithium-ion battery safety by preventing thermal runaway, which is a chain reaction of increasing temperature and pressure that can cause the battery to explode or catch fire. Thermal runaway can be triggered by various factors, such as short circuits, overvoltage, overtemperature, mechanical damage, or external heat sources.?

The BMS detects any abnormal conditions, such as high or low voltage, high or low temperature, high or low current, or low impedance, and takes corrective actions, such as cutting off the power, activating the cooling system, or alerting the driver. The BMS implements various safety mechanisms, such as fuses, circuit breakers, contactors, relays, and isolation switches, to isolate the faulty cells or modules, and prevent the propagation of thermal runaway to the rest of the battery pack.

For example, when a cell or module experiences a short circuit, the BMS detects the sudden drop in voltage and increase in current and opens the circuit breaker or contactor to disconnect the cell or module from the battery pack. When a cell or module is overcharged or over-discharged, the BMS detects the deviation from the normal voltage range and balances the cell or module by bypassing or diverting the current.?

When a cell or module is overheated or overcooled, the BMS detects the deviation from the normal temperature range and activates the cooling or heating system to adjust the temperature. When a cell or module is damaged or punctured, the BMS detects the change in impedance or resistance and isolates the cell or module from the battery pack.

Software and Hardware Upgradability of EV BMS

The software of a Battery Management System for electric vehicle can be updated to improve the performance, efficiency, and reliability of the battery. The software update can include new or modified BMS algorithms, parameters, or settings, which can enhance the accuracy, robustness, or adaptability of the BMS. Some BMSs can be updated remotely via wireless communication, such as Bluetooth, Wi-Fi, or cellular, while others require a physical connection to the vehicle or the charger.

The hardware of a Battery Management System for electric vehicle can also be upgraded or replaced, but this may involve more cost and complexity. The hardware upgrade or replacement can include new or improved sensors, actuators, or control units, which can increase the effectiveness, precision, or speed of the BMS. However, the hardware upgrade or replacement would typically also require compatibility checks, calibration procedures, and safety tests to ensure the proper functioning and integration of the new BMS components.

Role of BMS in Electric Vehicle Fleet Management

The Battery Management System has a growing role in electric vehicle fleet management, as it can provide useful data and actionable insights for electric vehicle fleet operators. A Battery Management System for electric vehicle can monitor health, status, and location of batteries, and send alerts or notifications for maintenance, charging, or replacement.?

Battery Management Systems can help fleet operators to:

  • Schedule the optimal times and stations for charging the vehicles, based on the SOC, SOH, and SOP of the batteries, and the availability and price of electricity.?

  • Optimize the load distribution and power consumption of the vehicles, based on the demand and supply of electricity, and the performance and efficiency of the batteries.?

  • Identify and diagnose faulty or degraded batteries, and plan for their repair or replacement.

BMS Data Analysis and Research

The Battery Management System for electric vehicle serves as a valuable tool for data collection and research. It offers insights into the battery’s performance, behavior, and degradation. Researchers and engineers leverage this data to understand the factors that affect the battery’s life and efficiency, and to develop new technologies and solutions for improving the battery’s design, operation, and management.

The data collection and research contribution of BMS can be exemplified by some projects and publications. For example, the Battery Lifetime Analysis and Simulation Tool (BLAST) is a software tool developed by NREL, which uses BMS data to simulate and analyze the battery’s performance and degradation under different scenarios and conditions.

Another example is the Battery Health Management (BHM) project, which is a collaborative effort by NASA, ANL, and other partners, which uses BMS data to develop and test novel algorithms and methods for estimating and predicting the battery’s health and remaining useful life. Furthermore, many academic papers and journals have used BMS data to conduct experiments and studies on various aspects of battery science and engineering, such as modeling, optimization, diagnosis, prognosis, and control.?

LOHUM’s research into millions of kilometers of EV battery performance data from EV Battery Management Systems has led to the creation of LOHUM DETX?, a battery future purchase price index that enables weighted buyback agreements.

Battery management systems are foundational to ensuring the safe, efficient, and prolonged operation of lithium-ion batteries in electric vehicles. It protects the battery from overcharging, over-discharging, overheating, or damage, and prevents thermal runaway in real-time. It facilitates and controls the energy flow between the battery and the vehicle’s systems, and optimizes energy utilization to maximize battery life and performance.

The Battery Management System for electric vehicle can be updated via software or hardware to improve its functionality and reliability. It also provides useful data and insights for electric vehicle fleet management and battery research and development. The battery management system is thus a key component in advancing the sustainable electrification of transportation and power infrastructure.

Understanding Battery Management System (BMS) – How It Works, Building Blocks, and Functions

When you step inside your electric car and switch it on, the cluster displays the distance you can go. You choose your pit brakes based on this range to reach your goal, but have you ever wondered how your car determines how far it can go?

The Battery Management System, often known as the BMS, monitors the battery pack that powers your electric car and calculates the range for you. The device also monitors the battery pack’s condition and guarantees its safety.

Lithium-Ion Cells and Battery Packs: An Overview

It’s crucial to comprehend how battery packs are manufactured before discussing Battery Management Systems.

A battery pack module is constructed of lithium-ion cells that are joined to one another to form an electric vehicle’s battery pack. To build a battery pack, further connections between these modules and other modules are made. This battery pack’s management is made easier and more serviceable thanks to the modular architecture. This design architecture enables the battery pack manufacturer to replace a damaged module as opposed to the entire battery pack.

A high power-to-weight ratio, excellent energy efficiency, low self-discharge characteristics, and strong high-temperature performance are just a few of the benefits that lithium-ion cells have to offer. Due to these qualities, lithium-ion cells are the preferred option for electric cars; nevertheless, these batteries are not without flaws, and solid-state battery technology is attempting to address these issues.

Another thing to keep in mind is that, when used within certain parameters, lithium-ion batteries can only provide the benefits indicated above. A summary of these operational constraints is provided below:

  • Voltage Requirements: Electric car battery packs are constructed using lithium-ion batteries. For context, consider that the Tesla Roadster has 6,831 cells, each of which must function within a specific voltage range. This range is often 3.0 to 4.1 volts for most cells. The battery pack’s lifespan and the performance it provides are reduced if the cells are utilized outside of these parameters.
  • Temperature Restrictions: Monitoring the temperature of lithium-ion batteries is necessary in addition to the voltage limitations. This range falls between -20 and 55 degrees Celsius for the majority of cells. The performance and longevity of the battery pack may be significantly reduced if the cells are operated outside of specified temperature ranges.
  • Current Draw: Monitoring the quantity of current being pulled from the cells is also necessary. The life of the cells shortens exponentially if the current taken from them exceeds the restrictions that are set.
  • Charging Current: Additionally, the battery pack must be watched while being charged. This is due to the rapid infusion of large quantities of electricity into the battery pack that often takes place during fast charging utilizing level 3 chargers. Because of the high current flow in the battery pack, the cells may overcharge, overheat, and lose life and efficiency.

A battery pack needs a Battery Management System because various variables must be maintained for it to operate at its best. A computerized system called the management system keeps track of a number of each cell’s properties and makes sure the battery pack runs within predetermined bounds.

Let’s dig into what is a Battery Management System?

The internal operating characteristics of temperature, voltage, and current are monitored and managed by a battery management system, or BMS, when a battery is being charged or drained. The BMS determines the State of Charge (SoC) and State of Health (SoH) of the battery to improve performance and safety. It guards against overcharging or over discharging the battery pack. By doing this, it keeps the charge level between the maximum and lowest permitted levels, preventing unexpected events like explosions. A BMS is therefore an essential tool for ensuring both the battery’s and the user’s safety.

Benefits of Battery Management Systems

  • Make sure the batteries run efficiently.
  • Monitoring battery status continuously to prevent an explosion.
  • Prolongs the life of the battery.
  • Shows battery level.

Battery Management System (BMS) Building Blocks

The four primary functional blocks are:

  • Cut-off FETs
  • Fuel Gauge Monitor
  • Cell voltage monitor
  • Temperature Monitor

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Cut-off Field-effect transmitters (FETs): Connecting the battery pack’s high side and low side using a FET driver creates an isolation barrier between the battery and the charger.

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Fuel Gauge Monitor: This helps to keep an eye on the charge that enters and leaves the battery pack. The quantity of charge flowing is calculated by multiplying current and time.

A 16-bit ADC with a low offset and high common-mode rating is used to measure the voltage of the sensing resistor, which is the most efficient and cost-effective method for monitoring current flow despite the fact that there are other methods. To achieve a wide dynamic range at a faster rate, a higher ADC is advantageous.

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Cell Voltage Sensors: One may classify cell voltage monitoring as a standard feature of the battery management system. It may be used to assess the battery’s condition. To ensure safety and extend battery life, all cells in a battery should function at normal voltage levels when being charged and discharged.

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Temperature Monitoring: As technology advances, batteries are designed to deliver large currents while maintaining a consistent voltage. Because batteries can unexpectedly explode due to a strong current flow forcing them to suddenly increase in temperature. It must be kept away from. To control the battery temperature to the rated value, the BMS continually monitors it.

It will alert you to start/stop charging or discharging if the temperature exceeds the rated value, this function is useful.

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Other Building Blocks:

  • Battery Authentication- Blocks the BMS electronics from being connected to the external battery pack.
  • Real-Time Clock (RTC)- Used in black-box software.
  • Memory- Used in black-box software
  • Daisy Chain- Makes connecting stacked devices easier.

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Battery Management System Working and Functions

A computer that is connected to several sensors is the Battery Management System. These sensors transmit data to the BMS about each cell’s voltage, current, and temperature.

After that, the Battery Management System examines this data to make sure that each cell is operating within the set parameters. If that isn’t the case, it tries to resolve the issue.

The BMS controls the cooling system to lower the battery pack’s temperature if the cells inside it get too hot. The Battery Management System balances the cells when there are changes in cell voltage. It transfers energy from one cell to another in order to balance the cells and guarantee that they are all running at the same voltage. The BMS also performs the actions mentioned above and logs the data it collects in order to assess the battery’s level of charge and overall health.

Functions of Battery Management Systems

Safety

Lithium-ion battery packs have a higher density, which raises the possibility of a fire. Therefore, as was already indicated, operating batteries at rated value is crucial.

This task is done for you by a BMS. It stops the battery pack from being overcharged or depleted to lengthen battery life.

Additionally, it protects short circuits, overcharging and over-discharging, anti-reverse charging, etc.

Modern BMS has Bluetooth and Universal Asynchronous Receiver-Transmitter (UART) connectivity capabilities.

Improvement of Battery Performance

A battery must function between the maximum and lowest rated values, i.e., current, voltage, temperature, etc., in order to work at its optimal level. A BMS aids batteries in operating within these crucial rated values, as we previously know.

It helps to guarantee uniform cell charging and discharge in the context of battery packs. As a result, the performance of the battery pack is substantially improved.

Along with improving performance, an effective battery management system helps to prolong the life of the battery packs.

Health Observation and Diagnostics

The amount of time needed to charge and discharge a battery depends on its degree of charge. A BMS can determine and display the amount of charge left in the battery.

By comparing these to the rated values, a BMS looks for anomalies in the battery parameter. Additionally, it has the ability to make adjustments to improve the battery’s health.

Final Thoughts

The cost, efficiency, and durability of any system must constantly be balanced in every design, though. Security is a single value that can never be underestimated. The BMS is unquestionably an undervalued component of an electric vehicle and requires the same consideration as the battery in terms of relevance and crew and vehicle safety.

Power plants, automobiles, electric vehicles, aviation, and other industries frequently employ battery packs. These rechargeable cells or battery packs are managed by battery management systems, which track the battery’s condition, compute secondary data, report that data, regulate its environment, authenticate it, and balance it. To protect the batteries from overcharging, blasting, and short-circuiting, it is essential to assess the protection features and dependability of the BMS.

eInfochips uses hardware-in-Loop technology for the Battery Management System Framework to assess and evaluate BMS functionality.

The framework can be used to test both linked items and apps. ?For each test case added to test management, the framework creates a feature file, runs the test using created keywords, and then uploads all test results using the framework libraries. Hardware-in-the-loop test of BMS controllers, Real time battery simulation in Simulink/Simscape, simulate battery voltage, capacity, and SOC parameters are some of the key features.

















Working of BMS

The main responsibility of a battery management system (BMS) is to ensure the safe and efficient operation of batteries by monitoring and controlling various elements such as voltage, current, temperature, and state of charge. The BMS corrects any parameter that goes above the safe operating range to avoid damage or safety risks. To avoid harm, the BMS may, for instance, lower the charging current if it notices that the battery is getting too charged. In a similar vein, the BMS can turn on cooling systems if the battery starts to overheat. The various components that make up a BMS cooperate to regulate the battery's performance. Among these components are sensors, communication interfaces, microcontrollers, and control circuits.

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  • Microcontroller: The microcontroller is the main processing unit of the BMS. It collects information from multiple sensors and uses that information to determine how best to regulate the battery's operation.

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  • Display: A display that shows current battery performance data, like temperature and charge level, is a feature of several BMS systems.

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  • Sensors: The majority of the battery's parameters, such as voltage, current, temperature, and charge level, are tracked by sensors. These sensors provide the data that the microcontroller needs to decide how to operate the battery.

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  • Alarm and Safety Features: Alarms and safety features in BMS systems can notify users of possible battery problems, such as overcharging or overheating. These characteristics can lessen the chance of accidents and increase battery life.

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  • Battery Balancer: Battery balancers assist in making sure that the charging and discharging of each cell in a battery pack occurs in a balanced manner. Harm can be avoided and the battery's lifespan can be extended by doing this.

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  • Communications Interface: The communications interface allows BMS to communicate with a wide range of other devices, such as the onboard computer of a car. Important diagnostic information about the state and operation of the battery can be obtained through this interface.

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  • Switches: Switches control the quantity of electricity that flows to and from the battery. They can be used in an emergency or in the event of a malfunction to disconnect the batteries.

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Together, these components comprise a comprehensive system that ensures the battery operates safely and effectively by monitoring and maintaining its performance.

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BMS design elements are numerous, but two crucial ones are capacity management and battery pack protection management. The two main areas of battery pack protection management are thermal protection, which uses passive and/or active temperature regulation to keep the pack within its safe operation area (SOA), and electrical protection, which means preventing harm to the battery from usage beyond its SOA.

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Electrical Management Protection: Current

Electrical safety is achieved by keeping an eye on battery pack current and cell or module voltages. Any battery cell's electrical SOA is limited by voltage and current. A well-designed BMS will preserve the pack by prohibiting operating outside of the manufacturer's cell ratings, which depicts a typical SOA for a lithium-ion cell. To extend battery lifespan, further derating is frequently used to stay inside the SOA safe zone. When charging or discharging, lithium-ion batteries have differing current limitations, though both modes can withstand larger peak currents for brief periods. In addition to peak charging and discharging current restrictions, battery cell manufacturers typically give maximum continuous charging and discharging current limits. A maximum continuous current will undoubtedly be applied by a BMS that offers current protection. To compensate for an unexpected shift in the load conditions, such as the rapid acceleration of an electric car, this could, nevertheless, come before. Peak current monitoring can be implemented by a BMS by integrating the current and, after delta time, choosing to either cut down on available current or completely stop the pack current. This enables the BMS to be both forgiving of high peak demands, provided they are not excessive for an extended period, and nearly immediate sensitive to severe current peaks, such as a short-circuit condition that has not triggered any resident fuses.

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Electrical Management Protection: Voltage

Within a specific voltage range, a lithium-ion cell can only function. The inherent chemistry of the chosen lithium-ion cell and the cells' current temperature will ultimately define these SOA bounds. These SOA voltage restrictions are typically further limited to maximize battery lifespan because any battery pack sees a large amount of current cycling, discharge owing to load demands, and charging from a variety of energy sources. The BMS needs to be aware of these boundaries since it will make judgments depending on how close these thresholds are. For instance, a BMS may ask for a gradual reduction in the charging current as it approaches the high voltage limit or, if the limit is achieved, a request for the charging current to be completely stopped. To avoid control, talk about the shutdown threshold, this restriction is typically complemented by extra intrinsic voltage hysteresis considerations. On the other side, a BMS will ask important active offending loads to lower their current needs when they get close to the low voltage limit. This can be accomplished in the case of an electric vehicle by lowering the traction motor's permitted torque. Naturally, to prevent irreversible damage to the battery pack, the BMS must prioritize the driver's safety above all else.

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Thermal Management Protection: Temperature

Lithium-ion batteries seem to have a broad temperature operating range on the surface, however, at low temperatures, chemical reaction rates noticeably slow down, reducing the overall battery capacity. They do function significantly better at low temperatures than lead-acid or NiMh batteries, but temperature control is still prudently necessary because charging below 0 °C (32 °F) might be physically troublesome. When charging below freezing temperatures, the anode may experience the phenomena of metallic lithium plating. This is irreversible damage that not only reduces capacity but also makes cells more prone to malfunction in the event of vibration or other stressful situations. By heating and cooling the battery pack, a BMS can regulate its temperature. The size, cost, and performance goals of the battery pack, as well as the design specifications of the BMS and product unit which may take the desired geographic region (e.g., Alaska versus Hawaii) into account all play a role in realized thermal management. Whichever kind of heater you have, it is usually more efficient to use an external AC power supply or a backup resident battery to run the heater when necessary. On the other hand, the main battery pack's energy can be extracted and used by the electric heater to heat itself if its current draw is low. The coolant that is pumped and dispersed throughout the pack assembly is heated by an electric heater if a thermal-hydraulic system is utilized.

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Capacity Management

Undoubtedly, optimizing a battery pack's capacity is among the most essential battery performance functions a BMS offers. Ignoring this maintenance could eventually cause a battery pack to lose its usefulness. The main cause of the problem is that a battery pack's "stack," or sequential arrangement of cells, is inherently slightly different in terms of leakage or self-discharge rates and is therefore not quite equal. Although it may be statistically affected by minute differences in the production process, leakage is a property of battery chemistry rather than a flaw caused by the manufacturer. A battery pack may contain well-matched cells at first, but as time goes on, factors like charge/discharge cycling, high temperatures, and normal calendar aging affect how similar cells are to one another in addition to self-discharge. The overall pack voltage is determined by the battery pack's series cell array, and while trying to charge any stack, a discrepancy between nearby cells can cause problems. Every cell in a perfectly balanced set will charge equally, and when the higher 4.0 voltage cut-off level is reached, the charging current can be stopped. The top cell will, however, reach its charge limit sooner in the unbalanced case, necessitating the termination of the leg's charging current before the other underlying cells have reached their full capacity.

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Types of BMS

To fulfill its primary command to "take care of the battery," battery management systems can be as basic or as complex as they want, incorporating a broad variety of technologies. On the other hand, these systems can be divided into groups according to their topology, which is related to the way they are set up and function on the various modules or cells that make up the battery pack.

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Centralized:

An energy storage system is referred to as centralized when every battery in the system is connected to a single BMS controller that oversees and regulates the entire battery pack. This type of BMS is frequently utilized in large-scale energy storage systems, such as those found in electric automobiles and power grids. Centralized BMS are typically less expensive than spread BMS since they require fewer sensors and communication links. The centralized design may have a single point of failure due to the wiring's potential complexity. The ability to offer a thorough picture of the battery pack and facilitate efficient control and administration of the complete system is one of the primary benefits of a centralized battery management system.

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Modular:

The BMS is split up into multiple identical modules, each with its own set of cables, and connects to a specific area of a battery stack next to it, much like a centralized implementation. These BMS submodules might occasionally be supervised by a principal BMS module, whose job is to keep an eye on the submodules' status and interact with external devices. Duplicate modularity makes maintenance and troubleshooting simpler, and it's easy to extend to larger battery packs. The drawbacks include slightly higher total expenses and, depending on the application, the possibility of redundant or underutilized capabilities.

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Distributed:

When every battery cell management system or module has its own BMS controller, which communicates with a master controller to operate the entire system, the system is referred to as a distributed BMS. Smaller-scale energy storage systems, such as those in electric cars or home energy storage systems, commonly use this type of BMS. Dispersed battery management systems (BMS) are recognized to be more adaptable and scalable than centralized BMS because of how easily they can be adjusted to changes or additions to the battery system. Furthermore, a distributed BMS can provide redundancy and fault tolerance because each cell or module has its own BMS controller. On the other hand, sensors and communication interfaces may come with more expensive and intricate wiring. The choice between a distributed and centralized battery management system (BMS) is influenced by several factors, such as the size and overall complexity of the battery system, the required level of redundancy and fault tolerance, the cost, and the wiring complexity limitations. Selecting the optimal battery management system (BMS) for a certain application is essential if you want to improve battery longevity, performance, and safety, among other advantages.

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Primary/Subordinate:

Though conceptually comparable to the modular architecture, in this instance, the master is devoted to processing and control in addition to external communication, and the slaves are more limited to just relaying measurement data. Therefore, similar to the modular types, the expenses might be cheaper because the slaves' functionality is typically simpler, meaning there is probably less overhead and fewer features that aren't used.

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BMS for Electric Vehicles (EV)

An electrical device that is frequently referred to as a "Battery Management System," or BMS, is essential for tracking and managing the performance of EV batteries. It regulates temperature, voltage, and charge level three vital factors for the secure operation of batteries frequently used in electric vehicles. When it comes to batteries used in electric vehicles, lithium-ion batteries are the most preferred type because of their high-power density, low self-discharge, and affordable price. Nevertheless, creating an electric car using a lithium battery carries several safety dangers in addition to its benefits. Because lithium-ion batteries can malfunction and even catch fire in uncommon circumstances for a variety of causes, including age, wear, thermal runaway, and overcharging or over discharging. To deliver safer e-mobility, this forces Automakers & OEMs to implement efficient Battery Management Solutions (BMS) to guarantee EV batteries are within ideal safety limits. A battery in an electric car combines multiple modules, each made up of a group of individual cells. Because each cell in each module tends to charge and discharge at a different pace, it is difficult to monitor battery pack performance. Furthermore, the factors of energy, health, and temperature all affect how each cell behaves. Therefore, for safer and more effective functioning, each battery cell needs to be independently observed. This is where the BMS comes into play; it monitors the parameters regularly and takes quick corrective action if it finds any irregularities. By ensuring the battery operates safely and dependably, this examination provides customers with an electric car that is both effective and secure.

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Battery Management Systems in EV come in two varieties: distributed and centralized.

The cost-effectiveness of a centralized BMS lies in its single control unit overseeing all cells; nonetheless, in the event of a control unit malfunction, the entire system is vulnerable to complete failure. In contrast, in a distributed BMS, several control units are commissioned to improve system resilience. This now entails higher expenses and complexity. Automobile manufacturers select the BMS system that best suits their needs and specifications; cost tends to favor centralized BMSs, while reliability favors distributed BMSs.

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As demonstrated by the following guidelines, the Battery Management System (BMS) is essential to the operation of electric vehicles in multiple ways.

  1. Cell Monitoring
  2. Thermal Management
  3. Cell Balancing
  4. Battery Optimization

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Benefits of BMS

Depending on the application, a complete battery energy storage system, or BESS, may consist of tens, hundreds, or even thousands of lithium-ion cells arranged strategically. With pack supply currents ranging up to 300A or higher, these systems may have a voltage rating of less than 100V or as high as 800V. Any misuse of a high-voltage pack has the potential to unleash a devastating, potentially fatal event. Therefore, to guarantee safe operation, BMSs are vital.

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Functional Safety

This is especially wise and necessary for large format lithium-ion battery packs, without a doubt. However, even smaller formats like those found in laptops, for example have been known to catch fire and do significant harm. Errors in battery management are rare in goods involving lithium-ion batteries since they compromise consumers' personal safety.

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Cost and Warranty Reduction

Batteries are costly and sometimes dangerous, and adding a BMS to a BESS raises expenses. More BMS control is required as the system is more complex since higher safety criteria go hand in hand with greater system complexity. However, a BMS's protection and preventive maintenance with regard to functional safety, longevity and dependability, performance and range, diagnostics, etc., ensures that it will save total expenditures, including warranty-related ones.

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Life Span and Reliability

The electrical and thermal protection management of the battery pack makes sure that every cell is used in accordance with the stated SOA specifications. This careful attention to detail guarantees that the cells are protected from harsh use and rapid cycles of charging and discharging, which will ultimately lead to a robust system that may offer many years of dependable service.

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Diagnostics, Data Collection, and External Communication

Continuous monitoring of all battery cells is one of the oversight jobs. Data recording can be used alone for diagnostics, but it is frequently utilized in conjunction with other computations to estimate the state of charge (SOC) of every cell in the assembly. While some of this data is used in balancing algorithms, it can also be used to tell external devices and displays about the battery pack's health, predict range or range/lifetime depending on current usage, and indicate the amount of energy available.

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Performance and Range

Optimal battery capacity can be achieved by BMS battery pack capacity management, which uses cell-to-cell balancing to equalize the SOC of nearby cells across the pack assembly. A battery pack could eventually become worthless without this BMS capability to take into account changes in self-discharge, charge/discharge cycling, temperature impacts, and general aging.

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Benefits of BMS for EV

BMS offers a number of noteworthy benefits for electric vehicles.

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Performance Optimization

With automated processes to address abnormalities and battery malfunctions, BMS assists in maximizing the performance of the battery packs to increase driving range and battery longevity.

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Real-time Data and Diagnostics

Real-time battery observation, data recording for logs on battery health, and defect identification are all done by BMS. This assists OEMs in planning preventative maintenance to address problems and greatly improve customer happiness.

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Safety and Reliability

Complete monitoring and safety features for overcharging, draining, and unexpected temperature fluctuations are included in BMS. This guarantees a battery's longevity and safety, reducing the likelihood of mishaps or battery failures for EV owners.

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Battery Maintenance and BMS

Routine maintenance is necessary to preserve the battery's longevity even though the BMS is intended to keep it operating correctly. A battery needs to be kept dry and clean, shielded from extreme heat, and neither overcharged or depleted in order to be maintained correctly. The BMS can also assist with battery maintenance by giving information on the battery's performance and alerting the user to any issues that need to be addressed.

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Trends of BMS

In order to improve their BMS capabilities and expand their line of automobiles, automakers continuously experiment. Several noteworthy advancements in the field of BMS include

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Intelligent BMS

BMS can enhance battery efficiency based on usage patterns, environmental factors, and other dynamic circumstances by utilizing sophisticated algorithms and machine learning approaches. Automakers benefit from this technology since it lowers warranty claims and improves their reputation for dependability.

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Advanced Predictive Algorithms

Advanced predictive maintenance systems are being linked with battery management systems in electric vehicles. These algorithms use real-time data to predict when battery components would need to be replaced or repaired. By doing so, they lower maintenance costs for customers, increase vehicle dependability, and improve brand reputation.

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External Communication

With BMS, wireless communication methods are being used more and more, allowing for quick system upgrades via Over-the-Air (OTA) updates. Automotive OEMs can maintain the functionality and performance of their BMS in the interim by applying updates on schedule.

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Soufiane Hamdaoui

I coach leaders to free up 20+ hours a month and implement systems that boost team performance by 20%

5 个月

Battery limits secured, performance sustained - BMS, the silent guardian.

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