CARB Filing Reveals Tesla Semi Battery Capacities

4680 Battery Specs

A fresh regulatory submission to the California Air Resources Board has disclosed the exact energy storage figures for the upcoming production versions of the Tesla Semi. The Long Range edition relies on an 822 kWh battery while the Standard Range model employs a 548 kWh unit.

The CARB Executive Order certifying the powertrain for the 2026 model year states that Tesla has selected Lithium-ion NMCA chemistry. This formulation reportedly supplies markedly greater energy density than a comparable mass of LFP cells. The top-spec Long Range variant lists a usable capacity of exactly 822 kWh paired with 800 kW peak power. Its shorter-range counterpart is engineered around a 548 kWh pack that delivers 525 kW to hit the targeted 325-mile range.

Both estimates assume the maximum gross combination weight of 82,000 pounds. Each configuration centers on Tesla’s second-generation 4680 cells, known internally as the Cybercell, and supports a peak charging rate of 1,200 kW (1.2 MW).

The Semi’s Efficiency

Public availability of the battery data now permits direct computation of vehicle efficiency. At the documented 500-mile range, the Long Range Semi consumes 1.64 kWh per mile. By contrast, a Model 3 requires roughly 0.250 kWh per mile—approximately one-sixth the figure—yet the passenger car weighs only 4,000 pounds against the Semi’s fully loaded 82,000 pounds.

Tesla engineers have therefore met the company’s original target of “less than 2 kWh per mile” under full load. Industry observers once questioned whether those numbers were realistic; the CARB documents now confirm the truck stays well below the threshold. Every incremental improvement beneath 2 kWh per mile delivers substantial operating-cost savings for freight fleets.

Why Cybercell?

Selection of the higher-cost NMCA 4680 cells over cheaper LFP alternatives addresses two critical commercial requirements: minimal tractor weight through superior energy density and robust thermal tolerance during repeated megawatt-scale charging. The resulting pack can absorb the heat generated by 1.2 MW sustained input, restoring approximately 300 miles of range in roughly 30 minutes and enabling fleet duty cycles comparable to conventional diesel tractors.

For reference, the AWD Long Range versions of the Model 3 and Model Y carry approximately 75-80 kWh batteries, rendering the Long Range Semi pack roughly 10 times larger.