CATL is raising battery production capacity in Chongqing to more than 20 GWh per year to back a long-term supply commitment to Seres and its Aito automotive brand.

The agreement, announced by the two companies, ties the world's largest battery maker to one of China's fastest-growing premium EV marques. Aito — the brand co-developed with Huawei and built by Seres — depends on CATL cells across its lineup, including the Aito 9 flagship shown in Paris.

Chongqing is the natural anchor for the deal. Seres builds its vehicles in the megacity, and CATL's local capacity expansion shortens the supply chain between cell plant and assembly line. Scaling beyond 20 GWh per year puts the site in the same tier as CATL's major dedicated campus plants serving single-OEM demand.

For context on scale: 20 GWh of annual cell output is enough to equip roughly 300,000 to 400,000 typical long-range EVs, depending on pack size. Aito's volumes have grown quickly enough that dedicated regional capacity now makes economic sense rather than drawing on CATL's broader allocation pool.

What does the agreement cover?

Beyond raw cell supply, the partnership spans several workstreams:

• Fast charging: the companies will cooperate on high-rate charging technology for Aito vehicles.
• Battery services: the deal extends into service offerings around the battery lifecycle.
• Overseas expansion: both sides plan to support Aito's push into foreign markets — a point underlined by the brand's presence at the Paris show.

The companies described the arrangement as a move to "secure their long-term collaboration on batteries for the Aito automotive brand."

Confirmed capacity versus stated intent

The Chongqing expansion above 20 GWh per year is the concrete number in the announcement. The fast-charging cooperation, battery services and international market plans are framed as elements of the agreement rather than programs with disclosed budgets, timelines or volume targets. Neither company has published a construction schedule for the added capacity or a date by which the 20 GWh threshold will be reached.

For Aito, the deal reduces a key strategic risk: cell allocation. Tier-1 battery supply has been a gating factor for EV brands scaling quickly, and a locked-in regional capacity commitment gives Seres planning certainty across future Aito model cycles.

What to watch next

Watch for a groundbreaking or commissioning date for the expanded Chongqing lines, any disclosure of the final capacity figure above the 20 GWh floor, and the first Aito models to carry batteries produced under the new agreement. The pace of Aito's export rollout — flagged in the deal — will signal whether CATL adds matching capacity outside China.