Lithium batteries are widely utilized in various electronic devices due to their high energy density and long lifespan. However, they are highly sensitive to overcharging and overdischarging, which can lead to thermal runaway and, in extreme cases, even explosions or fires. In order to mitigate these risks, lithium battery manufacturers have gradually developed pre-charging functions and thermal management systems.

This chapter primarily introduces the role and principle of the pre-charging function. By gradually increasing the battery voltage during the charging process, the pre-charging function effectively reduces the likelihood of overcharging and ensures the safe and reliable charging of the battery. This technology not only enhances the performance and lifespan of the battery but also protects users and devices from potential safety risks.

1. Let's talk about what pre-charging is

Due to the high energy density of lithium-ion batteries, direct entry into fast charging mode may cause damage to the battery, affecting its lifespan and potentially posing safety hazards. 

Although lithium batteries typically have built-in circuit protection during the design process to reduce the likelihood of overcharging, not pre-charging the battery can still pose various risks, such as circuit protection failure and self-discharge rates over prolonged periods.

Pre-charging mainly involves controlling the charging current and voltage to charge the battery at a lower current than during regular charging. This current is typically much lower than the current during regular charging. Through this process, the battery undergoes a certain degree of charge-discharge cycling before regular charging to activate the internal chemical substances of the battery, improving its charge-discharge performance and cycle life.

During pre-charging, the charging control circuit adjusts the charging current and voltage precisely according to the battery's state and charging requirements to achieve the optimal pre-charging effect. Through this process, the positive and negative electrode materials inside the battery are activated, reaching the optimal electrochemical state.

2. There are four advantages of lithium battery pre-charging

I. Circuit Protection: Pre-charging reduces the flow of current within the battery before the main circuit is completely closed, reducing the risk of circuit damage and enhancing the safety and reliability of the circuit.

II. Extended Battery Life: Pre-charging ensures a smoother and more stable charging and discharging process, prolonging the battery's lifespan. Improved Charging

III. Efficiency: Pre-charging pre-fills the battery with charge, improving charging efficiency and speed, reducing charging time and energy consumption.

IV. Battery Balancing: Pre-charging balances the charge within the battery and forms a protective layer, ensuring greater stability and safety during charging. 

Pre-charging enhances battery safety, prolongs lifespan, improves charging efficiency, and balances cells for stability.

3. Correct charging methods for lithium batteries include

I. Shallow discharge and recharge are more beneficial for lithium batteries. Deep discharge and recharge are only necessary when calibrating lithium batteries in the power module of the product. Therefore, products powered by lithium batteries do not need to adhere to specific charging processes. Convenience comes first, and you can charge at any time without worrying about affecting battery life.

II. Avoid charging at excessively high temperatures, as using lithium batteries in environments above the specified operating temperature (above 35°C) will result in a continuous reduction in battery capacity, reducing the supply time. Charging at such temperatures will cause greater damage to lithium batteries. Shallow discharge and recharge are more beneficial for lithium batteries. Deep discharge and recharge are only necessary when calibrating lithium batteries in the power module of the product. 

III. Use matching chargers for lithium battery charging and strictly follow the requirements.

IV. Lithium batteries will naturally activate during normal use, requiring no special methods.

V. The safe operating voltage range for lithium batteries is 2.8~4.2V. Going beyond this range may cause accidents, hence the need for specialized chargers.

VI. Chargers provide constant current to charge lithium batteries. As the battery voltage increases, the charger also increases the charging voltage to accelerate charging speed.

VII. The storage environment of lithium batteries should consider temperature and humidity. Avoid environments with excessively high temperatures and humidity to prevent damage to the batteries.

4. The charging process of lithium batteries can be divided into four stages

Trickle charging (low-voltage pre-charging), constant current charging, constant voltage charging, and charging termination. Pre-charging is necessary during the design process, and selecting the appropriate constant current value for battery charging is essential.

When it comes to battery safety, MeritSun's Serve Rack Module series is closely associated with the pre-charging function, a crucial feature of our solution.

The Serve Rack Module series is more than just a typical energy storage system; it's a comprehensive solution that incorporates advanced pre-charging technology.

This technology controls the charging current and voltage to perform charge-discharge cycles on the battery before it is put into use, activating the internal chemical substances of the battery to enhance its performance and lifespan, ensuring the battery pack remains stable and safe during the charging process.

Utilizing intelligent BMS technology ensures the battery is fully activated before use, providing you with a safer and more reliable energy storage solution.

Whether you're using it for telecommunications backup power, office buildings, or shopping malls, the Serve Rack Module series can provide continuous and stable power support, ensuring your energy storage system remains in optimal condition.

As lithium batteries become increasingly widespread and essential in our daily lives, understanding their safety features becomes more crucial. This functionality is not merely an add-on but an indispensable necessity in our lives.

It provides us with a solid guarantee for our increasingly battery-dependent lifestyle, allowing us to enjoy the convenience brought by technology with peace of mind while ensuring reliability in usage.

MERITSUN BATTERY GROUP

sales@meritsunpower.com