Sunwoda debuts 684 Ah storage cell, targets mass production in early 2026

China’s Sunwoda unveiled its 684 Ah large-format battery cell at the recently held EESA Energy Storage Exhibition in Shanghai, presenting what the company described as a stage-gate milestone in its in-house cell, pack and system capabilities.

The cell is designed for utility-scale and grid applications, with small-batch trials scheduled for Q4 2025. Mass production is planned to begin in Q1 2026, targeting an initial annual capacity of 10 GWh.

Technical features outlined by Sunwoda emphasize high single-cell capacity and system-level integration. The 684 Ah cell uses AI-enabled stacking and a three-dimensional thermal management structure and is compatible with 2,000V high-voltage platforms.

Sunwoda stated that a 20-foot container using the new cell can deliver an energy density of 6.9 MWh or higher, while reducing the number of cells in series and parallel, as well as structural components – cutting assembly time and footprint by around 50% and significantly lowering system integration costs.

According to the manufacturer, the cell achieves at least 12,000 cycles at 0.5P, supports 0.25P charge–discharge scenarios, and delivers system roundtrip efficiency of no less than 94.5%. The company says its lifecycle intelligent management will underwrite a 20-year warranty window across a range of grid-side and generation-side applications.

Sunwoda’s safety architecture integrates passive design with automated inspection systems. The company has implemented thermal-electrical separation to isolate high-voltage circuits from thermal components, enhancing operational safety. The new cell has undergone a rigorous safety validation process, comprising 62 tests, including overcharge, compression, and thermal runaway scenarios.

Sunwoda plans to initiate production of the new battery cell at two facilities in China – Nanchang (Jiangxi) and Quzhou (Zhejiang) – with a combined manufacturing capacity of 10 GWh per year to support initial deliveries. At EESA, the company announced it had signed a strategic cell supply agreement with an undisclosed systems integrator for 1.6 GWh. The first shipments are scheduled for Q1 2026, primarily targeting grid-side energy storage deployments.

Regulatory and market access efforts are actively underway. Sunwoda has begun the TÜV Rheinland certification process for its 684 Ah cell and is working to comply with EU carbon footprint and battery passport regulations, with market entry in key European countries – such as Germany and France – targeted for 2026. In the US, technical discussions are ongoing with AESI (formerly ABS), with a framework agreement expected by the end of 2025. The cell has also been selected for inclusion in a low-carbon industrial park initiative in Shanghai’s Jiading district, where Sunwoda plans to build a 100 MW project in collaboration with industry partners in 2026.

Sunwoda described the rollout of its 684 Ah cell as a strategic response to market trends favoring higher-capacity cells and greater system-level integration. The company forecasts storage battery shipments of 20–25 GWh in 2025, with the 684 Ah product expected to contribute over 30% of that volume. Sunwoda aims to capture a 5–8% share of the global energy storage market. According to the company, the 684Ah cell outperforms competing large-format cells in both energy density and cycle life, though independent validation will be essential as commercial deployments advance.