The Tesla Semi’s Battery Specs Are Finally Official and Diesel Should Be Worried

A new filing with the California Air Resources Board (CARB) has finally pulled back the curtain on the official battery specs for the 2026 Tesla Semi.

The document provides the first verified look at the usable energy capacity and power output for both the Long Range and Standard Range versions of the electric hauler (via @SawyerMerritt).

The CARB executive order confirms that Tesla is using a specialized lithium-ion chemistry known as NCMA (nickel-cobalt-manganese-aluminum). This specific blend is favored for heavy-duty applications because it offers high energy density while reducing the amount of costly cobalt required.

For the flagship Long Range model, the filing lists a usable capacity of 822 kWh. This massive battery pack supports Tesla’s target of a 500-mile range while carrying a full load. More impressive is the steady power rating of 800 kW, which translates to roughly 1,072 horsepower. This ensures the truck can maintain high speeds and performance even on steep grades.

The Standard Range model features a smaller but still substantial 548 kWh usable capacity. This version is expected to cover roughly 300 miles on a single charge, making it ideal for shorter regional routes. It is rated at 525 kW of steady power, or approximately 704 horsepower, providing plenty of muscle for standard hauling duties.

Signed on April 15, 2026, this certification is a critical step for Tesla as it ramps up production. It confirms that the Semi meets California’s zero-emission standards for heavy-duty vehicles, paving the way for more of these electric trucks to hit the road as Tesla expands its manufacturing capacity in Nevada.

Tesla just proved the skeptics wrong. Real-world 2026 data shows the Semi hitting 1.64 kWh/mile while hauling a full 82k lb load. By squeezing 500 miles out of an 822kWh pack, Tesla has moved the goalposts for long-haul logistics, putting traditional diesel economics on notice.