CATL and Seres announced a long-term strategic cooperation on 10 October 2026 that accelerates a second phase of a battery “plant‑in‑plant” inside Seres’ Chongqing Super Factory, bringing the two phases’ combined annual battery pack capacity to more than 20 GWh and confirming that AITO models will continue to use CATL batteries.
What the agreement says — production, scope and product continuity
According to company statements reported by industry outlets, the core of the deal is an accelerated second phase of CATL’s battery operation inside Seres’ factory that will add 10–12 GWh a year. Together with the first phase, the companies say the combined annual capacity will exceed 20 GWh. Reports state CATL began operating two CTP 2.0 battery pack lines at the Seres plant on June 30, 2025; the two firms did not disclose the exact capacity of the first phase or the start date for phase two.
The agreement also ties CATL battery supply to every model of Seres’ AITO brand going forward. Public reporting notes AITO has used CATL packs across its line-up and that cumulative AITO deliveries have passed 1.2 million vehicles, figures attributed in company statements cited by the sources.
Why this matters globally
The move is significant on three fronts: supply security for Seres/AITO, factory‑level integration of pack assembly, and a coordinated push into overseas markets.
- Supply certainty: committing AITO to CATL packs reduces sourcing risk for Seres as other OEMs pursue in‑house or alternative suppliers.
- Factory integration: building battery pack lines inside the vehicle plant (a “plant‑in‑plant”) shortens logistics between pack assembly and vehicle fitting, a step companies say improves cost competitiveness and supply‑chain resilience.
- Export strategy: the agreement reportedly includes joint work on super‑fast charging networks, battery services across the pack lifecycle, and coordinated market development in Europe, the Middle East and Central Asia.
How the scale compares with CATL’s global installations
Reports give the two‑phase Seres capacity as just over 20 GWh/year. Industry reporting places CATL’s global installations at hundreds of GWh: one account cited 333.0 GWh from January–August 2026 (39.4% share globally) while domestic Chinese installations for CATL were reported at 41.5% market share in August 2026. The Seres plant therefore represents a meaningful dedicated line for a single brand but remains a small fraction of CATL’s worldwide deployment.
Competitors and context — in‑house batteries and customer diversification
Multiple Chinese automakers are reported to be moving toward in‑house battery programs or alternative suppliers. The sources cite Li Auto, Xiaomi and XPeng as examples of OEMs pursuing self‑developed or other suppliers’ batteries; Li Auto said it would fit its own batteries across its lineup and planned an equity move into Sunwoda Power, while Xiaomi announced partnerships with CALB and Sunwoda Power for its Longjia/Dragon Armor batteries. These separate reports frame the Seres/CATL pact as a counterweight to customer diversification.
Financial and operational limits mentioned in the reporting
Seres reported a net loss attributable to shareholders of 1.717 billion yuan for H1 2026 and falling revenue and sales in 2026; reporting attributes these pressures to rising raw materials costs (including batteries and chips) and asset impairments. The companies did not disclose the duration or financial terms of the new CATL‑Seres agreement, nor the precise first‑phase capacity or the timetable for phase two production start.
Ambiguities and disagreements in the sources
Sources agree on the main points — a 10–12 GWh phase two, combined capacity above 20 GWh, and continued CATL supply for AITO — but several details remain unspecified by the companies and therefore inconsistently reported:
- Exact capacity of phase one: one outlet calculated it as “more than 8 GWh” by simple subtraction, but the companies did not publish a figure.
- Phase‑two start date: articles note the companies did not say when the second phase will start production.
- Agreement length and financial terms: neither duration nor money were disclosed publicly in the coverage examined.
Practical implication checklist for OEMs and fleet buyers
If you are an OEM evaluating supplier strategy, or a fleet buyer tracking battery supply risks, use this checklist to interpret similar plant‑in‑plant announcements:
- Confirm whether the internal lines assemble packs only or also produce cells; in this case reporting specifies pack (CTP 2.0) lines inside the vehicle factory.
- Check explicit capacity disclosures for each phase rather than inferred math; companies here published the phase‑two range (10–12 GWh) but not phase‑one capacity.
- Request contract duration and supply guarantees before assuming exclusivity; media reporting states duration and financial terms were not disclosed.
- Assess local incentives and taxes that affect economics: reporting mentions a China consumption tax on lithium‑ion batteries (2% from September 1, 2026, rising to 4% from September 1, 2027) and exemptions for sodium‑ion and solid‑state batteries until end‑2028.
- Map export ambitions to tariff exposure in target markets; Automotive World commented the overseas push gives AITO options outside the EU, where China‑built EVs face extra import duties.
Limitations and unanswered questions to watch
Key open items that will determine how consequential the expansion becomes:
- Precise timing and commissioning date for phase two production.
- Official confirmation of phase‑one capacity to validate the reported >20 GWh total.
- Contractual length and exclusivity details tying CATL supply to AITO models.
- How Seres will fund higher battery purchase commitments while reporting H1 2026 losses.
- Which specific AITO models and which export markets will be prioritized under the joint market development plan.
Bottom line
CATL’s acceleration of a second phase inside Seres’ Chongqing factory formalizes a deep supply link between the battery leader and the AITO brand, aiming for over 20 GWh/year of battery pack capacity and coordinated work on charging, services and overseas sales. The announcement secures supply for AITO at a moment when several auto groups are diversifying or building in‑house battery programs; however, the absence of published phase‑one capacity, financial terms and a clear phase‑two start date leaves the full operational and commercial impact to be determined.