Demand Side: Surge in Energy Storage Installations Shifts Custom PACK Design from Optional to Essential
Industry data indicates that China requires approximately 1,700 to 2,100 GWh of new energy storage capacity during the “15th Five-Year Plan” period, with an average annual increase of 300 to 400 GWh. Given that new installations of advanced energy storage in China totaled approximately 107 GWh in 2024, the average annual installation volume over the next five years must exceed three times that figure. Meanwhile, by the end of 2025, long-duration advanced energy storage stations (capable of discharging for four hours or more) accounted for 27.6% of total installed capacity. Energy storage is shifting from a mere “auxiliary facility” to a critical component for ensuring peak-load power supply.
Different projects impose distinct requirements regarding battery PACK capacity, discharge rates, cycle life, and operating environments, making custom design a pivotal step in system integration.
Supply Side: Core Capabilities of Custom Design Companies
Companies specializing in the custom design of energy storage battery PACKs typically require four key capabilities: first, cell selection and grouping, involving the choice of chemical systems (such as LFP, ternary lithium, or sodium-ion) and capacity tiers based on the target system;
second, structural design and thermal management, utilizing simulations to optimize series-parallel topologies, mechanical structures, and heat dissipation/insulation strategies; third, BMS and electrical design, enabling functions such as cell balancing, protection, and remote monitoring; and fourth, certification and mass production, ensuring compliance with testing standards like UN38.3 and IEC 62133 while maintaining batch consistency.
According to industry research estimates, the global market for custom battery packs is valued at approximately $23 billion in 2025 and is projected to grow to $34.7 billion by 2030, representing a compound annual growth rate (CAGR) of about 8.5%.
Industry Trends: Large-format Cells and System-level Delivery
The industry is currently witnessing two major trends.
On one hand, battery cells are evolving toward larger capacities; data from InfoLink indicates that the market penetration of large cells exceeding 500Ah in China is approaching 5% in the first quarter of 2026 and is expected to reach 20% for the full year.
Larger cells mean fewer individual cells, connection points, and sampling nodes, leading to reduced assembly and O&M costs. On the other hand, pack design is shifting from standalone customization to system-level delivery, with modular, scalable architectures and intelligent BMS becoming standard features.
Custom design firms must coordinate across multiple levels—cells, modules, packs, and systems—to strike the right balance between cost reduction and safety.
Key Factors for Selecting a Custom Design Firm
Industry experts advise energy storage integrators and project owners to focus on the following when evaluating custom pack design firms: design simulation and validation capabilities (availability of coupled thermal-electrical-mechanical simulation and prototype testing systems); supply chain and cell sourcing stability; BMS software development and iteration capabilities;
certification and quality management systems; and transparency regarding timelines and costs from prototyping to mass production.
For specialized operating conditions—such as long-duration energy storage or extreme temperature environments—it is also essential to verify the firm’s track record regarding environmental adaptability.
Trends and Outlook
Looking ahead, as economic requirements for energy storage become more stringent and standards tighten, custom pack design will increasingly rely on digital simulation and data feedback, benefiting companies with full-chain engineering capabilities.
For purchasers, evaluating both custom design capabilities and the stability of mass-production delivery is crucial to controlling the total lifecycle costs and risks of energy storage projects.
