Automotive Cells Company (ACC) has celebrated its five-millionth French-made battery cell, just as shareholder Stellantis prepares to temporarily halt production at two factories because of insufficient battery supplies. So, behind the motor show glamour, there are still some caveats of mass production.
Insufficient supply
How can a battery supplier meet its contractual commitments and still leave its biggest customer short of batteries? That is the awkward question hanging over Automotive Cells Company (ACC), the joint venture between Stellantis, Mercedes-Benz and TotalEnergies subsidiary Saft.
At the Paris Motor Show, ACC proudly displayed its five-millionth cell manufactured in France. The milestone is significant for a company established to help Europe reduce its dependence on Asian battery manufacturers. Yet just two weeks earlier, Stellantis announced temporary production shutdowns at its French factories in Sochaux and Rennes.
The reason? Insufficient battery supplies for long-range electric SUVs, precisely the vehicles that depend on ACC’s homegrown technology.
Affected vehicles
ACC insists that it is meeting its agreed delivery schedules. That does not necessarily contradict Stellantis’ complaints. The battery manufacturer may be fulfilling its contractual commitments while still producing too few cells to satisfy unexpected demand for particular models.
The affected vehicles include the electric Peugeot E-3008 and E-5008, alongside the Citroën C5 Aircross. They belong to a broader portfolio of nine Stellantis models supplied by ACC, including the Opel Grandland, Jeep Compass, Lancia Gamma and DS N°7 and N°8.
These are strategically important vehicles, particularly as European manufacturers try to convince families to switch to electric SUVs. But customers choosing the longest-range versions have faced delays of up to eight months.
With help from Cina
As recently as February, ACC was reportedly producing enough batteries for barely 1,000 cars per month. The company was struggling with high rejection rates at its Billy-Berclau/Douvrin gigafactory in northern France.
Chinese battery specialists were brought in to help overcome the manufacturing problems, an uncomfortable irony for a venture built partly around European technological independence.
There are signs that the intervention, alongside ACC’s broader industrial improvements, is paying off. According to the company’s latest figures, module production in September alone almost equaled its entire output for 2025.
Rejection rates are also approaching their targets, ACC says, although it has not disclosed the actual percentages. That makes it difficult to establish how close the factory is to achieving consistently competitive yields.
Next challenge
The five million cells produced so far have supplied batteries for nearly 40,000 electric cars. It is a tangible achievement, but modest compared with the scale of Europe’s automotive industry.
The company now faces another challenging step. Next to its first production block, which supplies Stellantis, a second block, adding 12.9 GWh of annual capacity, is scheduled to start operating in 2027. Its customer will be Mercedes-Benz, ACC’s other automotive shareholder. A third block will be added in the final phase to reach roughly 60 GWh of annual production.
That expansion means ACC must simultaneously improve the performance of its existing production lines and successfully commission new ones. Not an easy task in Europe.
ACC CEO Allan Swan used the five-million-cell milestone to insist that Europe can industrialize advanced battery technology at scale. But he also called for a regulatory framework that would allow European manufacturers to compete on a level playing field.
Enough cells for EU demand?
Whether Europe will eventually produce enough cells to satisfy its own automotive industry remains contested. The European Automobile Manufacturers’ Association (ACEA) warned in September that domestic production could fall short of proposed localization requirements. Environmental organization Transport & Environment disputes that assessment, arguing that sufficient capacity could be available if planned projects materialize.
So far, ACC has demonstrated that it can manufacture advanced NMC battery cells in Europe, and that its output is accelerating. What it has yet to demonstrate is that it can produce them reliably, competitively and in the quantities its customers require.
