22 Years' Battery Customization

What Happens to a Lithium-ion Battery Pack Without a Protective Board?

Oct 09, 2023   Pageview:427

Lithium-ion batteries have revolutionized the way we power our portable electronic devices. From smartphones to laptops and electric vehicles, these energy-dense power sources have become an integral part of modern life. However, they come with their own set of challenges, particularly when it comes to safety. 

One crucial component in ensuring the safety and longevity of a lithium-ion battery pack is the protective circuit board. This board, commonly referred to as the Battery Management System (BMS), plays a vital role in safeguarding the battery from a range of potential risks.

The Role of the Battery Management System

The BMS is the guardian of a lithium-ion battery pack. It monitors and manages various aspects of the battery's operation, including voltage, current, temperature, and state of charge. Its primary functions include:

Overcharge Protection: Preventing the battery from charging beyond its safe voltage limits.

Over-discharge Protection: Safeguarding against excessive discharge, which can lead to irreversible damage or reduced capacity.

Temperature Monitoring: Keeping the battery within a safe operating temperature range, guarding against overheating or extreme cold.

Cell Balancing: Ensuring that individual cells within the battery pack are charged and discharged evenly, which is crucial for maximizing overall battery life?

Short Circuit Protection: Detecting and mitigating potential short circuits that could lead to catastrophic failures.

Without a functional protective board, a lithium-ion battery pack is left vulnerable to these risks, which can have severe consequences.

3.2V 20Ah Low Temperature Square LiFePO4 Battery Cell
3.2V 20A Low Temp LiFePO4 Battery Cell -40℃ 3C discharge capacity≥70% Charging temperature:-20~45℃ Discharging temperature: -40~+55℃ pass acupuncture test -40℃ maximum discharge rate:3C

Cycle Life

The cycle life of a lithium-ion battery refers to the number of charge and discharge cycles it can undergo before its capacity significantly degrades. This critical parameter is directly influenced by the presence or absence of a protective board, also known as the Battery Management System (BMS). Let's delve into the intricate relationship between cycle life and the absence of a protective board in a lithium-ion battery pack.

Cell Imbalance and Uneven Aging

In a multi-cell lithium-ion battery pack, each cell undergoes a slightly different aging process due to variances in capacity and internal resistance. Without a BMS to actively balance the charge among cells, these discrepancies become more pronounced over time. Some cells may experience premature aging due to overcharging, while others suffer from over-discharging. This cell imbalance further accelerates the degradation of the battery pack as a whole.

Increased Susceptibility to Temperature Extremes

Lithium-ion batteries are sensitive to temperature variations. Without a protective board, the battery pack becomes more susceptible to extreme heat or cold. Operating in these conditions exacerbates the degradation process, leading to a shorter cycle life. Additionally, exposure to high temperatures can accelerate the growth of internal resistances, further diminishing the battery's performance and longevity.

Heightened Risk of Catastrophic Failure

Perhaps the most alarming consequence of a missing protective board is the heightened risk of catastrophic failure. In the absence of safeguards against overcharging, over-discharging, and short circuits, the battery pack becomes a potential hazard. The unchecked release of energy can lead to thermal runaway, resulting in fires, explosions, or other hazardous incidents.

Low Temperature High Energy Density Rugged Laptop Polymer Battery 11.1V 7800mAh
Low Temperature High Energy Density Rugged Laptop Polymer Battery Battery specification: 11.1V 7800mAh -40℃ 0.2C discharge capacity ≥80% Dustproof, resistance to dropping, anti - corrosion, anti - electromagnetic interference

Overcharge, Over-discharge and Short Circuit

The absence of a protective board, commonly known as the Battery Management System (BMS), leaves a lithium-ion battery pack vulnerable to a trio of serious risks: overcharge, over-discharge, and short circuit. Understanding these dangers is crucial in appreciating the vital role that the BMS plays in safeguarding these energy-dense power sources.

Overcharge: A Looming Hazard

Overcharging a lithium-ion battery occurs when it continues to receive a charge even after reaching its maximum safe voltage level. This can lead to the formation of metallic deposits, known as lithium plating, on the battery's anode. These deposits compromise the battery's capacity and structural integrity, resulting in reduced performance and a shortened lifespan. Without a protective board to regulate charging, the risk of overcharge significantly escalates.

Over-discharge: A Silent Menace

Conversely, over-discharge transpires when a battery is drained beyond its safe lower voltage threshold. This leads to the formation of harmful structures called lithium dendrites on the anode. These microscopic protrusions can puncture the separator, causing internal short circuits and accelerating the battery's degradation. The absence of a BMS allows over-discharge to occur unchecked, hastening the deterioration of the battery's capacity and longevity.

Short Circuit: A Catastrophic Scenario

A short circuit is a direct electrical connection between the positive and negative terminals of a battery. Without a protective board, there are no safeguards in place to prevent this potentially catastrophic event. A short circuit leads to an uncontrolled release of energy within the battery pack, resulting in rapid overheating, potentially leading to fires, explosions, or other hazardous incidents.

Protective Board Composition 

The protective board, also known as the Battery Management System (BMS), is a critical component in ensuring the safety and optimal performance of lithium-ion battery packs. Understanding its composition sheds light on the sophisticated technology that underpins the protection of these energy-dense power sources.

Microcontrollers and Processors

At the heart of the protective board are microcontrollers and processors. These sophisticated electronic components serve as the brain of the BMS, executing complex algorithms and calculations. They monitor key parameters such as voltage, current, temperature, and state of charge, making real-time adjustments to maintain safe operating conditions.

Voltage Sensors

Voltage sensors play a pivotal role in the BMS by continuously measuring the voltage of each individual cell within the battery pack. This data is crucial in preventing overcharge and over-discharge, as it allows the BMS to intervene if any cell's voltage exceeds or falls below safe limits.

Current Shunts

Current shunts are precision resistors that measure the current flowing in and out of the battery pack. By precisely monitoring current, the BMS can prevent situations like overloading or over-discharging, ensuring that the battery operates within its designed parameters.

Temperature Sensors

Temperature sensors are strategically placed throughout the battery pack to monitor the operating temperature. This information is vital in preventing overheating or exposure to extreme temperatures, which can lead to degradation or, in extreme cases, catastrophic failure.

Cell Balancing Circuits

In multi-cell battery packs, cell balancing circuits play a critical role. They ensure that each cell receives an equal charge during charging and discharging cycles, preventing cell imbalance. This process maximizes the overall capacity and lifespan of the battery pack.

Protection Circuitry

Protection circuitry encompasses a range of components, including fuses, relays, and MOSFETs. These elements act as fail-safes, disconnecting or isolating faulty cells or sections of the battery pack in the event of an abnormal condition, such as a short circuit.

Communication Interfaces

Many BMS units incorporate communication interfaces, such as CAN (Controller Area Network) or SMBus (System Management Bus). These interfaces facilitate communication between the BMS and external systems, providing data and control capabilities for integrated battery management solutions.

*
*
*
*
*

Leave a message

Contact Us

* Please enter your name

Email is required. This email is not valid

* Please enter your company

Massage is required.
Contact Us

We’ll get back to you soon

Done