The Development Trend of Home Energy Storage Cells

Family Energy Storage is one of the highly regarded gold tracks in the industry. From the products on the market, the energy storage capacity of home energy storage systems is generally between 5-35KWh, with 10-20KWh being the most common.

Although the price of lithium carbonate has fallen to 200,000 yuan/ton, the battery core is still the core component of the system, accounting for about 50% of the cost. Home energy storage batteries mainly include square, soft pack, and cylindrical batteries. In terms of single cell capacity, square batteries range from 50Ah to 100Ah, soft pack batteries range from 30Ah to 80Ah, and cylindrical batteries range from 10Ah to 50Ah.

Home energy storage is a typical end product. When choosing products, end users not only consider the cost-effectiveness of the products, but also factors such as lifespan, functionality, and brand.

Portable storage extends to home energy storage

Currently, the boundary between home energy storage and portable energy storage in the range of 2 kWh to 8 kWh is gradually becoming blurred, with an increasing level of integration between the two.

In the past, home energy storage was primarily concentrated in the range of 5 kWh to 15 kWh, while portable energy storage products often had power ratings below 1.5 kWh. The supply of power products within the range of 2 kWh to 8 kWh did not meet demands adequately.

Since 2022, some portable energy storage companies have started extending their products into the realm of home energy storage. According to research by GGII (Global Green Energy Industrial Research Institute), portable energy storage products with a capacity of 6 kWh can achieve system capacities of over 20 kWh through plug-and-play and modular series-parallel configurations. Among these, several leading portable energy storage companies are accelerating their entry into the home energy storage market, and home energy storage companies, considering ecosystem layout and product supply capabilities, are also entering the portable energy storage market. In the future, the boundaries between the products of both segments will become increasingly indistinct.

Clear Trends in Home Energy Storage Battery Functionality

In response to the demands for flexibility and intelligence in home energy storage, the design capabilities of home energy storage batteries need to be stronger.

While home energy storage may appear to focus primarily on storage, battery management and whole-house energy allocation are equally important. Therefore, the core competitiveness of home energy storage batteries lies in their product design capabilities.

In the design of energy storage battery products, the main focus is on compatibility with energy storage inverters (with varying requirements across countries/regions) and customized product design based on customer needs.

For instance, the battery management system (BMS) in the energy storage system needs to be compatible with the energy storage inverter. The energy storage inverter controller communicates with the BMS through the CAN interface, obtaining battery pack status information and enabling protective charging and discharging of the battery to ensure safe operation.

The energy storage BMS must have the capability to monitor real-time battery voltage, current, and temperature, thereby calculating battery state of charge (SOC), state of health (SOH), and other battery parameters, enabling functions such as battery balancing, thermal management, and fault alerts.

In 2022, due to a surge in overseas demand for home energy storage, there was a shortage of home energy lithium batteries with a main capacity of 50Ah, and battery cell manufacturers accelerated their capacity expansion. As the household storage industry is in a rapid growth phase with incremental market penetration being the main driver, positive competition among enterprises has yet to become intense.

Small Cells of 50Ah and Below Remain Dominant

In comparison to "large" cells used in grid-scale energy storage, "small" cells dominate the home energy storage sector.

Smaller individual cell capacities enhance battery adaptability, enabling a greater variety of module configurations and energy capacities. This facilitates matching with household storage and portable energy storage systems of varying energy capacities.

In terms of individual cell capacities, large cylindrical cells range from 10Ah to 50Ah, square cells range from 50Ah to 300Ah, and pouch cells range from 30Ah to 80Ah.