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Li-ion Battery Packs and Inverters: Choosing Between CAN, RS485, and RS232 Communication

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Why is it essential for a lithium battery pack to communicate with an inverter? Can't it function without communication? The energy storage landscape has seen rapid advancements over the years, particularly in sectors like photovoltaics,Battery recycling machine where costs in the lithium battery industry have significantly declined. This progress has allowed for more widespread applications in photovoltaic power generation, household energy storage, industrial and commercial energy storage, electric vehicles, and charging stations worldwide. Notably, China has emerged as a major global player with the most competitive and influential presence in these markets.

Energy storage systems are not a new invention; they have been utilized since World War II, with German U-boats using large quantities of lead-acid batteries. These submarines employed diesel generators to charge lead-acid batteries while on the surface,cylindrical battery pack mahcine and the batteries provided power during submersion. However, due to the low energy density of lead-acid batteries, submarines couldn't stay submerged for extended periods and had to surface frequently for recharging, making them vulnerable to attack.

Lead-acid batteries have straightforward discharge curves and low energy density. With their simple voltage-based power estimation, they operated without requiring sophisticated battery management systems (BMS) for prolonged periods. As the commercial application of lithium batteries has grown,cell stacking machine the situation has evolved. Lithium batteries offer over five times the energy density and cycle life of lead-acid batteries, presenting challenges in managing their energy density, as slight mismanagement can lead to issues such as combustion or explosions.

The two most common lithium battery types are lithium ternary and lithium iron phosphate batteries, each with specific voltage characteristics. For instance, a single lithium ternary cell carries a nominal voltage of 3.7V, while a lithium iron phosphate cell has a nominal voltage of 3.2V. Initially, lithium batteries were used individually or in pairs, producing output voltages of 3.7V or 7.4V, simplifying their applications with low consistency requirements. However, as the energy storage capacity has increased, the voltage levels have risen significantly.

For example, a ternary battery pack with an output voltage of 300V requires around 81 cells connected in series, making battery consistency crucial. Without proper consistency, certain cells within the series might exhibit different capacities. When charged, the higher-capacity cells fill up more quickly than the lower-capacity ones, causing overcharging. During discharge, the higher-capacity cells deplete faster, potentially resulting in overdischarge. In both cases, these deviations can damage lithium batteries and, at worst, lead to fires or explosions. This scenario underscores the importance of having an effective Battery Management System (BMS) to monitor and manage each cell within the battery pack.

In scenarios where the energy storage system features relatively small power requirements and gentle charging and discharging conditions, relying on the BMS for hardware control can be sufficient. However, high-power energy storage products demand lithium battery packs with communication capabilities. These batteries need to inform the inverter of real-time operating parameters, including voltage, current, power, and temperature, as these characteristics influence the battery's behavior. Each cell may vary slightly, and inverter systems might not have the capacity to account for these differences. Hence, it is imperative that the lithium battery communicates with the inverter to relay real-time data about its state. Armed with this information, the inverter can adjust its control strategy to optimize the performance, lifespan, and safety of the battery. Consequently, energy storage systems with a capacity exceeding 5 kWh must feature communication capabilities.

As a wise netizen has pointed out, lithium battery packs with communication capabilities offer an additional benefit: they enable real-time tracking of each battery cell's performance over a network. However, not all platforms make this data accessible to end-users.

Most lithium battery packs come equipped with RS232/RS485/CAN interfaces, which might leave you wondering which one to use. In terms of preference, the recommended order is CAN/RS485/RS232. For larger battery pack configurations, CAN bus is the optimal choice, considering its widespread use in automotive and railway systems. This makes CAN the top choice for safety and speed.

What makes stacking and winding different from one another?

The winding corner of the winding process has radians from the inside of the cell, and the space utilization rate is lower. The battery area can be fully utilized during the stacking process, and the cell generated under the same volume of cell design has a better energy density.