In the current era of rapid development in energy storage technology, Battery Management Systems (BMS) have become crucial components to ensure the safe and efficient operation of batteries. Whether it is electric vehicles, energy storage systems, or various portable electronic devices, BMS plays an irreplaceable important role. Next, we will delve into the working principles of Battery Management Systems.
Battery voltage is one of the key indicators reflecting its operational status. The BMS uses high-precision voltage sensors to monitor the voltage of each individual battery cell and the total voltage of the battery pack in real-time. Taking a lithium-ion battery pack commonly used in electric vehicles as an example, a pack might contain hundreds of individual cells, each with a relatively narrow normal operating voltage range, where even slight voltage deviations could indicate changes in battery performance.
Accurately measuring the current magnitude and direction during battery charge and discharge processes is crucial for the BMS to calculate the charge and discharge amounts, evaluate the battery's power output capability, and determine the battery's working status. Current sensors typically use Hall effect principles or shunt principles to convert the battery charge and discharge current into measurable voltage signals.
During charging, the BMS can control the charging rate by monitoring the current magnitude, preventing overcurrent charging that could damage the battery; during discharging, based on current data, the BMS can calculate the remaining battery power in real-time, providing users with accurate power information.
Battery performance is extremely sensitive to temperature, with too high or too low temperatures severely affecting battery lifespan, charging and discharging efficiency, and safety. Therefore, the battery management system needs to place multiple temperature sensors at key positions of the battery pack to collect temperature information in real-time. Common temperature sensors such as thermistors and thermocouples can convert temperature changes into electrical signals and transmit them to the BMS for processing.
In high-temperature environments, the chemical reaction rate inside the battery increases, which may cause the battery to overheat or even experience thermal runaway; in low-temperature environments, the viscosity of the electrolyte increases, the ionic conductivity decreases, the internal resistance of the battery increases, and the charging and discharging performance declines. By monitoring the battery temperature in real-time, the battery management system can activate cooling or heating devices when the temperature exceeds the normal range, ensuring that the battery always operates within a suitable temperature range.
The BMS monitors the battery voltage and charging current, and when it detects that the battery voltage has reached the preset cutoff voltage while the charging current has not yet dropped below the specified value, it will immediately activate the overcharge protection mechanism. At this time, the battery management system will control the charging circuit to cut off the charging power, preventing the battery from continuing to charge. Additionally, some advanced BMS also adopt pre-protection strategies, gradually reducing the charging current when the battery voltage approaches the cutoff voltage to avoid increasing the overcharge risk due to high current near full charge.
The battery management system monitors the battery temperature in real-time through temperature sensors, and when the temperature exceeds the preset safety threshold, it activates the overheat protection mechanism. On one hand, the BMS will control the charging and discharging power of the battery, reducing the rate of heat generation; on the other hand, it will activate cooling devices such as fans or water-cooling systems to accelerate battery cooling, keeping the battery temperature within a safe range.
With continuous advancements in energy storage technology, the functions and performance of Battery Management Systems developed by Gerchamp will also continue to be optimized and improved, injecting strong momentum into the rapid development of the energy storage industry.
English
