CATL has begun trial production of battery cells at its plant in Debrecen, Hungary — a facility with a designated cell production capacity of 100 GWh, making it the Chinese battery maker's largest manufacturing base outside China.

The company confirmed it fulfilled all preconditions required to start the trial run earlier this month. Trial production exists to set up, optimize and validate production equipment and manufacturing processes before series output begins. CATL disclosed no date for the start of volume cell production.

The timing marks the end of a three-year build-out. CATL broke ground on the Debrecen site in 2023 and launched battery module assembly there in autumn 2024. Since then, the plant has supplied 537,000 battery modules to clients. Installation of cell manufacturing equipment finished in the second quarter of 2026, and the company obtained all relevant permits before triggering the trial run.

CATL said in a statement that the plant, positioned as "a strategic manufacturing hub," will supply "the most well-known, leading European automakers, which have already built significant electric vehicle production capacity in Hungary in recent years." The company added that it has installed "the most advanced, flexible production lines in Debrecen in order to fulfil the needs of its valued clients at all times." Those claims rest on the company's own account; series output volumes will be the test.

On compliance, CATL said management of the Debrecen facility "continues to work closely with the authorities in order to ensure that high standards are maintained in terms of the environment, and the health and safety of its employees."

Debrecen is CATL's second plant in Europe. Its first, near Erfurt in Germany, has been operational since 2023 and supplies batteries to BMW, Mercedes, Volkswagen Group and Stellantis. Hungary's attraction is clear: several European OEMs have assembled EV production capacity in the country, putting CATL's cells within short logistics reach of vehicle assembly lines.

The 100 GWh figure is a designated capacity, not current output. Closing the gap between a permitted, trialing plant and a fully ramped 100 GWh site will take sustained equipment validation, customer qualification runs and stable demand from the automakers CATL names as its target base.

What to watch next: the transition from trial runs to confirmed series cell production at Debrecen, the pace of the ramp toward the 100 GWh capacity milestone, and the first named European OEM programs the plant will feed.