40.1% - The Layer the Stack Race Has Already Lost

The automotive transition is usually described as a shift from internal combustion to electric. That framing captures the technology change. It misses the structural one.

The internal combustion engine (ICE) value chain was vertically integrated around the original equipment manufacturer (OEM). Automakers controlled the powertrain, the platform, the brand, and the distribution. Margin flowed to them because they owned the critical layers. The electric vehicle (EV) transition did not just change the powertrain. It disaggregated the stack.

Battery chemistry, vehicle architecture, operating software, compute infrastructure, and distribution have become distinct, contestable layers. Different companies are racing to control each one. Whoever controls a layer that others depend on captures structural leverage and the margin that follows. I’ve has called this the Stack Race in previous memos.

The battery layer holds a specific position in that race. Battery performance and cost set the competitive ceiling for every electric vehicle built above it. Range, charge time, and purchase price are determined at the cell level before a vehicle is designed around them.

One number makes the current state of that layer very interesting. 40.1%.

Contemporary Amperex Technology Co., Limited (CATL) held 40.1% of global EV battery installations from January through April 2026, per SNE Research via the Korea Battery Industry Association. That figure covers batteries installed in electric and plug-in hybrid vehicles specifically, not grid storage or consumer electronics.

BYD ranked second at 14.2%. BYD manufactures its own batteries exclusively for its own vehicles. Its supply is not available to other OEMs. Among suppliers other OEMs can actually source from, the nearest competitor is LG Energy Solution at 9.1%, with its share declining year over year.

The three non-Chinese players in the top ten are LG Energy Solution, SK On, and Panasonic. Each is either losing share or growing below the market average. Seven of the top ten global EV battery suppliers are Chinese firms, accounting for 72.2% of global installations.

Market share is a business metric. Infrastructure is a structural condition. The distinction matters here.

CATL's customer base spans virtually the entire global automotive industry. Western OEMs including Tesla, BMW, Volkswagen, Mercedes-Benz, Hyundai, and Ford source from CATL, as do major Chinese automakers including NIO, Li Auto, Xiaomi, and Geely. These companies compete aggressively against each other at the vehicle layer. At the battery layer, they share a common dependency on the same supplier. Tesla is reportedly CATL's single largest customer.

At 40.1%, the strategic question for OEM procurement teams shifts. It moves from which battery supplier to prefer toward what the terms of a dependency look like when alternatives at scale are limited. A supplier holding more than twice the share of its nearest external competitor, and supplying the majority of the world's major automakers, occupies a different structural position than a preferred vendor.

A parallel in semiconductor manufacturing makes the structural condition more concrete. TSMC holds roughly 60% of global semiconductor foundry capacity. The semiconductor industry does not primarily debate whether to use TSMC. It debates how to manage the strategic implications of needing TSMC. The EV battery market has not reached that point. At 40.1% and widening, it is moving in that direction.

Government policy was real. China's Ministry of Industry and Information Technology placed CATL on a 2017 white list of approved battery manufacturers. Companies not on the list faced difficulties securing factory licenses. CATL gained preferential access to government contracts and associated tax benefits. China's broader EV subsidy programs created domestic demand at a scale that gave CATL volume ahead of any foreign competitor.

Founder Robin Zeng's decade-long affiliation with the Chinese People's Political Consultative Conference (CPPCC), beginning in 2013, provided access to policymakers that engineering credentials alone would not have opened. Policy and positioning worked together.

But CATL had to out-compete more than 200 other Chinese battery companies to reach its current position, including BYD and China Aviation Lithium Battery (CALB), both of which received the same policy tailwinds. Subsidies explain why the field existed. They do not explain who won it.

That distinction matters for how OEM strategists and policymakers think about what comes next. Policy can theoretically respond to subsidies through tariffs and domestic investment mandates. A decade of compounding capital investment, manufacturing scale, and engineering depth is a different challenge on a different timeline.

Tesla is CATL's largest customer. Tesla is also building its now lithium iron phosphate (LFP) factory near Gigafactory Nevada, using manufacturing equipment purchased directly from CATL, with CATL personnel assisting in equipment setup.

When a layer approaches infrastructure status, customers do not simply accept the dependency. They begin building their own version of it. In Tesla's case, the infrastructure provider is, in effect, supplying the tools and expertise for the alternative.

Whether Tesla's factory represents the early stages of a viable exit from battery dependency, or a new and more complicated form of it, is an open question. What it illustrates is the strategic logic major OEMs might be working through.

This memo applies TaaSMaster's Stack Race framework to the global EV battery layer. For how cost architecture shapes competitive positioning at the vehicle layer, see "The Platform Belongs to Leapmotor. The Brand Belongs to Stellantis. Where Does the Margin Go?"

SNE Research via Korea Battery Industry Association and CnEVPost: global EV battery market share data, January through April 2026. IEA Global EV Outlook 2026: Chinese producer market share analysis. Interconnected (December 2024): CATL founding history and competitive context. Foundation for Defense of Democracies: Robin Zeng and CPPCC affiliation. Reuters: Tesla as CATL's largest customer.

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