Chinese technology manufacturer Jiangsu Zhongtian Technology Co., Ltd. (ZTT) has introduced its latest large-scale battery solution, the ENERGRID NA7, a 7.58 MWh liquid-cooled energy storage system designed for grid and renewable energy applications.
The system made its debut at the 13th Energy Storage International Conference and Expo (ESIE2025) in Beijing and is housed within a standard 20-foot shipping container. It is engineered for a variety of use cases, including shared energy storage projects and renewable energy integration.
At the core of the ENERGRID NA7 is ZTT’s self-developed 3S-integrated power conversion system (PCS), supporting 2000 V high-voltage DC input and AC grid connection. The integrated bidirectional DC/AC inverter consolidates what is traditionally a multi-stage energy conversion process into a single step, enabling conversion efficiency levels exceeding 99%.
Compared with its previous generation, the NA7 increases energy density per unit area by 51% and boosts single-container capacity by 51.6%, without changing container dimensions. Each battery module delivers more than 210 kWh per pack and features an IP67 protection rating, allowing reliable operation in harsh outdoor environments.
Thermal management is handled through a modular liquid cooling system coordinated with the battery management system (BMS), maintaining cell temperature differences within 2°C. According to the company, this precise control extends module lifespan by more than 30%. Structurally, the container incorporates high-strength steel and corrugated panel reinforcement, achieving seismic resistance rated at level 9 and enabling safe stacking and transport in extreme environments such as high-altitude and desert regions.
Electrically, the NA7 integrates an embedded energy management system (EMS) capable of sub-20 millisecond switching, making it suitable for grid frequency regulation and peak-shaving applications that demand rapid response. Fire safety is addressed through a three-tier detection architecture at the cabin, cluster and pack levels, complemented by both water-based and gas-based suppression systems.
Through a three-dimensional spatial layout and modular integration, the NA7 reduces footprint by 40% compared to conventional 5 MWh container systems, shortens installation cycles by 60% and lowers total lifecycle operation and maintenance costs by 25%, according to ZTT.
The 2000V DC platform also includes reserved interfaces for future expansion to 8 MWh without structural hardware modifications, supporting scalability as project requirements evolve.
ZTT positions the ENERGRID NA7 as a solution to common storage market challenges, including low voltage ratings, conversion losses and inefficient space utilization. The system has entered the industrial validation phase and is being prepared for broader deployment across renewable energy storage, grid-side peak shaving and commercial and industrial applications, underscoring the company’s vertically integrated capabilities from battery materials to intelligent system control.
