What is Active Balance?

Intro

Active balancing technology plays a crucial role in optimizing the performance and safety of battery systems. As energy storage applications continue to grow in various industries, it becomes essential to manage the voltage imbalances that exist within battery packs. This is where active balance comes into play.

In this article, we will explore the concept of active balance and its significance in battery systems. We will delve into how active balancing works, its benefits, and the applications where it is commonly employed. Whether you are a technology enthusiast or an industry professional, understanding active balance can provide valuable insights into improving the efficiency, lifespan, and safety of battery-powered devices.

So, let’s begin our journey into the world of active balance and discover how it revolutionizes battery management.

What is Active Balance in Lithium Battery?

Active balancing of lithium batteries refers to the process of achieving similar voltage levels for each individual cell within a lithium battery pack during charging. A lithium battery pack consists of multiple individual cells, which may have voltage variations due to capacity differences or uneven usage.

During charging process, some single cells may reach their rated voltage and stop charging, while others may not be fully charged yet. If this difference persists, it can result in certain cells within the battery pack cycling more frequently than others, leading to performance and lifespan issues for the entire battery pack.

An active balancing charging system monitors the voltage of each individual cell within the battery pack and takes measures to address any differences. Typically, it will apply additional charge to cells with higher voltage or temporarily disconnect cells with lower voltage from the circuit and redirect the current to other cells to achieve voltage balance. This ensures that each cell reaches a similar voltage level, improving the charging efficiency and performance of the entire battery pack while prolonging its lifespan.

There are various ways to implement active balancing of lithium batteries, including integrating balancing circuits in chargers, using dedicated Battery Management Systems (BMS), or installing balancing modules within the battery pack. These methods aim to maintain consistent states for individual cells within the lithium battery pack, enhancing overall stability, performance, and safety.

Reality Applicated Examples

Here are typical examples of applications that utilize active balancing technology to manage voltage differences within battery packs, achieve balanced charging between individual cells, enhance overall performance and lifespan, and ensure safe and stable operation of the systems.

1. Electric vehicles: Electric vehicles use high-capacity lithium battery packs as their power source. Due to small variations between individual cells within the battery pack, prolonged usage and cycling can lead to some cells having higher or lower voltages. To maintain battery pack performance and lifespan, electric vehicles employ active balancing technology in their battery management systems. This technology redistributes current from cells with higher voltage to those with lower voltage, achieving a balanced charging state for the battery pack.
2. Drones: Some drones are powered by lithium batteries to provide the required flight power. During flight, the battery pack of a drone undergoes charging and discharging cycles, which may result in voltage imbalances among the individual cells. To ensure flight stability and safety, the battery management system of drones utilizes active balancing to adjust the voltage differences between the cells, thus maintaining the stability of the battery pack.
3. Solar energy storage systems: Solar energy storage systems employ lithium batteries to store energy generated from solar panels. With the charging and storing of solar energy, voltage differences may occur among the individual cells within the battery pack. By applying active balancing technology, the system can monitor and adjust the voltage between the cells, ensuring consistent states during charging and discharging processes and improving the efficiency and performance of the solar energy storage system.

What you Need to Mind about Active Balance?

Let’s move on. Here are some considerations to keep in mind when actively balancing lithium batteries:

BMS selection

Choosing the right Battery Management System (BMS) for your application is critical. The BMS is responsible for monitoring and managing the battery pack’s status and controlling the active balancing operations. Ensure that you select a reliable BMS that is compatible with your battery, as it will contribute to improved performance and safety.

Balancing algorithm selection

Different balancing algorithms are suitable for different application scenarios. Select the appropriate balancing algorithm based on the characteristics and requirements of your battery pack to achieve optimal voltage balancing effectiveness and performance.

Charge and discharge state limitations

Active balancing operations are typically performed during charging. Ensure that the battery pack undergoes active balancing in a safe charging state and follow the recommendations and specifications provided by the battery manufacturer to prevent overcharging or over-discharging.

Temperature monitoring and control

Temperature is a critical factor that affects lithium battery performance and lifespan. When performing active balancing, pay attention to monitoring and controlling the temperature of the battery pack to prevent damage from excessively high or low temperatures.

Safety precautions

Take necessary safety measures when conducting active balancing operations. For example, use balancing circuits and protective devices that comply with safety standards to prevent issues such as overcurrent, overvoltage, and overheating.

Regular inspection and maintenance

Regularly inspecting and maintaining the battery pack is crucial. Check the individual cell’s status, the operation of the balancing circuit, and make adjustments and maintenance as needed to ensure the proper functioning of the active balancing system.

These are some considerations for actively balancing lithium batteries. Proper active balancing operations can enhance battery pack performance and lifespan. However, it is important to follow relevant safety guidelines and recommendations and choose the appropriate balancing strategies and equipment based on your specific circumstances. If you have any questions or concerns, it is recommended to consult professionals or battery manufacturers for more detailed and accurate advice.

Q&A

Is active balancing necessary for lithium batteries to pass certification?

Not all lithium batteries require active balancing to pass certification. Battery certification is typically based on overall performance and safety characteristics of the lithium battery, rather than solely considering the balancing charging function. For example, according to international standards such as UN 38.3 and IEC 62133, the main focus of lithium battery certification includes aspects such as chemical stability, charge-discharge performance, temperature tolerance, vibration and shock tests, short circuit protection, and more.

However, in certain application areas such as power tools, electric vehicles, and drones, the balancing charging function of lithium batteries may be required or recommended. Balancing charging ensures that the voltage of each individual cell within the battery pack stays within a reasonable range, thus enhancing battery performance, lifespan, and safety. Such requirements are often due to the variations in capacity between individual cells within the battery pack.

In conclusion, active balancing charging is not a mandatory requirement for lithium battery certification. However, in specific application areas, it may be required or recommended to ensure the performance and safety of the battery pack. Specific requirements should be determined based on relevant standards, application needs, and manufacturer guidance.

Which kinds of devices do not require active balancing batteries?

Active balancing batteries are typically used in devices that require large-capacity battery packs to ensure voltage balance among individual cells within the pack. Here are some examples of devices that do not require active balancing batteries:

1. Small portable electronic devices: Portable electronic devices such as smartwatches, Bluetooth earphones, small speakers, etc., usually use small-capacity lithium polymer or lithium-ion batteries. Due to the small battery capacity and fewer cells, the voltage differences are minimal, and there is no need for batteries with active balancing functionality.

2. Low-power consumer electronics: Some low-power consumer electronics like digital thermometers, remote controls, electronic scales, etc., often use button cells or alkaline batteries. These batteries have small capacities, small voltage differences, and the devices themselves have low power consumption, so active balancing batteries are not required.

3. Sensors and monitoring devices: Sensors and monitoring devices typically employ low-power hardware, such as wireless sensor networks, environmental monitoring devices, etc. These devices usually use small-capacity batteries with minimal voltage differences, and active balancing batteries are not necessary.

4. Children’s toys: Children’s toys generally use small-capacity batteries like alkaline or button cells. Since the battery capacity is small and voltage differences are minimal, batteries with active balancing functionality are not needed.

All in all, relatively small and low-power devices typically do not require active balancing batteries. However, regardless of the device, it is important to choose reliable and safety-compliant batteries and use and maintain them correctly according to the manufacturer’s guidelines to ensure proper functioning and safe use of the devices.

Does a juicer require a lithium battery with active balancing?

For small household appliances like juicers, it is generally not necessary to use lithium batteries with active balancing functionality.

The active balancing function is primarily designed to address voltage differences that may occur during the charging and discharging processes of large-capacity lithium battery packs. Juicers typically use small lithium batteries with relatively small capacities, resulting in minimal voltage differences within the battery pack. Therefore, there is no need to employ active balancing technology. Additionally, incorporating an active balancing system would increase costs and complexity, and it might occupy more space in small household appliances.

For juicers, selecting standard lithium batteries with appropriate capacity and quality is sufficient to meet their normal operational requirements. However, when choosing batteries, it is still important to consider factors such as battery quality, safety, and endurance to ensure the juicer operates efficiently and safely. During usage, please follow the guidelines for battery use and maintenance to extend battery life and ensure safe usage.

Do all small household appliances not require lithium batteries with active balancing?

Not all small household appliances do not require lithium batteries with active balancing functionality. While many small household appliances can use regular lithium batteries, some small appliances with high power or high capacity requirements may need to use lithium batteries with active balancing functionality.

Here are some examples of small household appliances that may require lithium batteries with active balancing:

1. Cordless handheld vacuum cleaners: Some higher-performance cordless handheld vacuum cleaners, due to their high power demands, typically use large-capacity lithium-ion battery packs. To ensure voltage balance among the individual cells within the battery pack, lithium batteries with active balancing functionality may be needed.

2. Portable wireless speakers: Certain high-power portable wireless speakers require large-capacity lithium batteries for extended playback time. Due to their higher power consumption, lithium batteries with active balancing functionality may be necessary to maintain voltage balance among the individual cells within the battery pack.

3. Portable power tools: High-power portable tools such as electric drills and lawnmowers often require large-capacity lithium batteries to provide durable and stable power output. To ensure voltage balance among the individual cells within the battery pack, lithium batteries with active balancing functionality may be needed.

4. Portable electric vehicles: Portable transportation devices like electric scooters and e-bikes require high power and long battery life. These types of devices typically utilize large-capacity lithium battery packs, and lithium batteries with active balancing functionality may be required to maintain voltage balance among the individual cells within the battery pack.