Three-fifths of EV battery fires occur while the vehicle is parked. Three out of five, or 60 percent, are fires that occur without any mechanical influence! During the initial quarter of 2023, approximately 640 incidents were reported in the media. Among these cases, 24.5 percent occurred during the charging process, and 35.5 percent happened while the vehicles were parked. These numbers are very scary, and there is nothing we can do about these accidents, but we can work together to find out what is causing them and what can be done to improve battery safety and prevent the risk of battery accidents. In this article, we will mention BMS and battery protection board, two solutions for battery safety protection, and explore more possibilities for battery protection.
Why Do Batteries Explode?
Battery fires happen all the time. From electric buses and EVs to home and grid-scale energy storage systems, the costs of inadequate security monitoring can be substantial and irreversible.
The concept of battery safety is often inseparable from incidents of battery fires and thermal runaway. Thermal runaway is fundamentally an inherent danger associated with stored energy. In batteries, it happens when either external or internal factors lead to the release of stored energy from the battery at a rate that surpasses its ability to disperse, leading to an uncontrolled temperature rise within the battery. Instead of the potential violent discharge, fire, and smoke that may follow, this situation occurs. If the battery can be sufficiently cooled naturally or through forced means to dissipate this extra heat, it is possible to prevent thermal runaway from happening.
Potential Risks in the Battery Life Cycle
Overcurrent and overvoltage: The potential implication of going above or exceeding the operating limit may cause the circuit to fail due to oxidation, sometimes resulting in short circuits. This can also destroy battery life, deteriorate life, and sometimes may lead to hazards such as fire or explosion.
Thermal management: Efficient batteries, especially lithium-ion, are very fragile. Even a minor temperature rise or minimal battery damage can result in thermal runaways and short circuits, ultimately causing explosions and fires. This is why battery thermal management solutions are extremely important.
In general, the acceptable temperature of the battery is:
32˚F to 113˚F (0˚C to 45˚C ) for charging
–4˚F to 140˚F (-20 C to 60˚C) for discharging
32˚F to 68˚F (0˚C to 20˚C) for storing
Fire protection: The hardest and most insidious threat to battery packs is battery fire safety. If the battery has factory defects, such as defects in the battery packaging and panels, it can cause internal short circuits, which can lead to sparks, smoke, and flames.
Cybersecurity: Protecting the safety of the battery is not enough to ensure that every key parameter is operating within the normal range, but also consider the safety of these parameters, if the data is stolen or maliciously tampered with, it can also lead to accidents.
MOKOEnergy’s BMS Solutions for Battery Safety
1. BMS
A BMS is an electronic system that oversees a rechargeable battery, whether it’s a single cell or a battery pack. It performs various functions such as assessing its condition, computing additional data, transmitting this information, safeguarding the battery, regulating its surroundings, and ensuring it remains evenly charged. This system is capable of tracking the battery’s condition through various indicators.
For Overcurrent and Overvoltage
We tackle this problem by incorporating voltage and current monitoring into both the software and hardware components of the BMS. This setup enables the use of circuit breakers to interrupt the circuit and halt the battery charging process whenever there are deviations from acceptable parameters. Here is an example of our basic hardware:
- Current and voltage transformers
- The amplifiers and buffers have resistor dividers for increasing the value of the output current and voltage
- An analog-to-digital converter that converts current and voltage values into digital signals
- Microcontroller (MCU) for reading signals
For Thermal Management
One of the most critical aspects to pay attention to when designing a BMS is the safety of the battery pack. The thermal management system of the battery safety and energy storage system relies on factors like the battery’s temperature coefficient and operations such as heating and cooling. It is equipped with thermistors to oversee the temperature coefficient within its operational limits. When the BMS detects any temperature deviation, it automatically performs the actions required for lithium-ion safety concerns and security. In some cases, the charging power may be cut off.
For Fire Protection
One of the most effective methods for reducing the risk of fire is to incorporate smoke detectors within the battery pack. Furthermore, the utilization of a battery cooling system provides an additional layer of protection for the battery, where a switch linked to the BMS is employed to enable or disable the cooling mechanism.
For Cybersecurity
Whenever data transmission is involved, there is always a risk of breach of confidentiality and integrity and, therefore, BESS is also vulnerable to cyber-attacks. Without strong BMS security features, the system is not immune from unauthorized access and various malicious activities that can severely damage the battery and associated BESS components.
In the custom BMS we built for the client, the user sends an authentication request and enters a login name and password. Once authentication is completed, the user will receive automatic authorization. They also receive a list of access rights that are used to verify what is allowed and what is not. After that, each subsequent request sent by the user is checked for permission. This greatly ensures the safety of battery data transmission.
2. BMS Board
Compared with BMS, although the equipment and functions of the BMS Board are relatively simple, it is also an indispensable part of the battery. There are also multiple BMS boards in BMS, and BMS boards are more suitable for small-scale applications. The role of the BMS board is reflected in the charging and discharging protection of series and parallel battery packs, and it can detect the status of overvoltage, overcurrent, overtemperature, under voltage, and short circuit of every single battery in the battery pack to extend the battery life. It is essential for preventing lithium-ion battery safety or battery packs from exploding, catching fire, or getting damaged.
For Overcharge Protection
The overcharge protection function means that when the voltage exceeds a certain range, the charger is forbidden to continue to input voltage. That is to control the overcharged MOS tube into the off state and stop charging.
For Over-discharge Protection
Unlike its operation during overcharge detection, the over-discharge protection feature halts the discharge of the load when the battery voltage decreases. The control over the discharge of the MOS tube into the off-state no longer discharges.
For Overcurrent Protection
The primary role of the overcurrent protection feature is to halt the discharge process when a significant current load is being drawn. This function serves to safeguard both the battery and the MOS tube, ensuring the battery and charging safety while in operation. Following the detection of an overcurrent situation, the battery will resume its regular operation once it has been disconnected from the load, allowing it to be recharged or discharged as usual.
For Short Circuit Protection
A short circuit happens when there is a creation of a low-resistance pathway connecting two locations in the circuit, leading to an overflow of current. In the case of batteries, a short circuit can lead to a rapid release of energy, generating heat and potentially causing thermal runaway, fire, or explosion.
In a word, with many years of experience in the industry, MOKOEnergy has a deep understanding of battery protection and is fully aware of the importance of preventing potential battery risks, so it can provide reliable and efficient solutions. With an R&D team of up to 70 people, our experienced team of engineers has extensive experience in designing and developing BMS and battery protection board solutions for various applications, including lithium-ion batteries, battery packs, and energy storage systems. With a deep understanding of lithium battery safety technology, battery voltage, and battery cells, they can design BMS and battery protection board solutions that can monitor battery voltage and provide battery balance. Our products are in line with global certification standards, such as EN15194:2017, CE, FCC, CB, UL, etc., demonstrating our commitment to quality charging and battery safety.
Conclusion
Batteries are fragile, and any fluctuation in voltage, current, temperature, or short circuit can lead to disaster. The most feasible way to enhance battery pack security is through integration with battery management systems. The BMS and BMS board can safeguard the battery pack against a range of possible risks, including excess current, sudden ignition, and fluctuations in temperature and voltage.
As a well-known manufacturer of BMS and BMS boards, MOKOEnergy has a wide range of state-of-the-art equipment and expertise in handling batteries safety. We are capable of tailoring battery safety solutions to match your precise requirements, covering everything from the initial design phase to manufacturing and rigorous testing. To request a complimentary consultation, please click here.
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