Tesla says a shortage of batteries, rather than weak demand, is what held back its car sales in the third quarter of 2026. In its shareholder letter, the company wrote that "battery availability continued to be the limiting factor in increasing auto volumes in the quarter." It also said it ended the period with "the largest backlog for our passenger vehicles in four years."

The explanation has been taking shape for some time. In the second quarter, Tesla described battery pack capacity as "the main limiting factor to near-term vehicle production volume increase." The latest letter goes further, suggesting batteries constrained what the company could actually sell during the quarter. Tesla did not put a figure on the backlog, though it reported record deliveries in Canada, Australia, Japan and Taiwan, along with record production at Gigafactory Berlin. Elsewhere, the letter says Tesla is focused on "increasing production across our factories" because of "strong demand."

The company's reported numbers are harder to square with that picture. Tesla delivered 486,532 vehicles in the third quarter, down 2% from 497,099 a year earlier. Model 3 and Model Y deliveries slipped 1%, while the "other models" category, which covers Cybertruck, Semi and the remaining Model S and X vehicles, dropped 48% to 8,295 units.

Tesla built 464,391 vehicles in the quarter, meaning it delivered 22,141 more than it produced. It was the second consecutive quarter in which the company drew down inventory, following a first quarter in which it built roughly 50,000 more cars than it sold. Global inventory fell to 11 days of supply, compared with 27 days in the first quarter and 15 in the second.

Production of the Model 3 and Model Y ran at an annualized pace of about 1.83 million units. Tesla lists installed capacity of more than 2.25 million units for the two models across its Fremont, Shanghai, Berlin and Texas plants, implying the factories operated at roughly 81% of capacity.

Pricing is another sticking point. Among the reasons it gave for revenue not growing, Tesla cited a "lower vehicle average selling price (ASP)" year over year, even after excluding currency effects. Carmaker that cannot build vehicles fast enough would typically raise prices or at least ease off discounting.

The letter does point to other uses for Tesla's battery cells. Energy storage posted its "highest-ever order rate and backlog," Megafactory Texas began production with 50 GWh of planned capacity, and Tesla is increasing 4680 cell output "to support the ramps of both Cybercab and Tesla Semi along with higher Model Y volumes." The company's outlook also says deliveries depend on "allocation decisions between sale to customers and use for our owned and operated fleet," suggesting part of the constraint reflects Tesla's own choices about where cells go.

Electrek, which first reported on the letter's details, called battery supply a real issue and noted that tariffs on Chinese cells complicate matters in the US. Still, it argued that falling deliveries and lower selling prices are not typical of a supply-constrained company. Its assessment was that the truth is likely a mix: demand recovered somewhat in certain markets, while Tesla is directing more cells toward energy storage, Cybercab and Semi because it sees those businesses as more valuable. That, it said, is a reasonable strategy, but not the same as having more customers than it can serve.