CARB Filing Confirms Tesla Semi Battery Sizes: 822 kWh Long Range, 548 kWh Standard Range
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California's Air Resources Board has officially confirmed the battery specifications for both Tesla Semi variants through CARB Executive Order A-374-0095, signed April 15, 2026. The regulatory filing reveals that the Long Range Semi carries an 822 kWh usable battery pack, while the Standard Range comes in at 548 kWh — both using NCMA lithium-ion chemistry built around Tesla's 4680 cells.
The specifications end years of speculation. Elon Musk publicly estimated the Long Range battery at "around 900 kWh" during a 2022 investor presentation. The production number lands 78 kWh lower while still achieving the same 500-mile range target — reflecting weight reduction and efficiency improvements Tesla achieved between prototype and mass production.
The Official Specifications
CARB's Executive Order is a legally binding certification document, making it the most authoritative source available for production vehicle specs. The filing covers both variants of the Semi that entered high-volume manufacturing on April 29, 2026, at a dedicated facility adjacent to Gigafactory Nevada — the same complex where Tesla produces its 4680 cells.
| Specification | Long Range | Standard Range |
|---|---|---|
| Usable battery capacity | 822 kWh | 548 kWh |
| Cell chemistry | NCMA 4680 | NCMA 4680 |
| Range (82,000 lb GCW) | 500 miles | 325 miles |
| Peak motor output | 800 kW (1,072 hp) | 525 kW (704 hp) |
| Peak charging rate | 1.2 MW (MCS 3.2) | 1.2 MW (MCS 3.2) |
| Energy consumption | 1.7 kWh / mile | ~1.69 kWh / mile |
The 1.7 kWh per mile figure for the Long Range model translates to 0.6 miles per kWh — a number that compares favorably to early leaked efficiency estimates and positions the Semi as a commercially viable alternative to diesel on high-frequency corridors within its range envelope.
Why 822 kWh Instead of 900 kWh
Musk's 2022 figure was a prototype-era estimate, and the gap between 900 kWh and 822 kWh reflects three years of engineering refinement before volume production began.
"Tesla Semi Long Range will have around 900 kWh."
— Elon Musk, investor presentation, 2022
The production vehicle achieves the same 500-mile range at 82,000 pounds gross combination weight with 8.7% less battery capacity. Weight reductions across the drivetrain, frame, and battery enclosure — combined with improved aerodynamics — mean fewer kilowatt-hours are needed to push the truck the same distance. In practical terms, 78 kWh less is roughly equivalent to removing the battery from six Tesla Model 3 Long Range vehicles while maintaining identical haul-weight range performance.
Charging: 1.2 MW and 30 Minutes to 60%
The Semi uses the Megawatt Charging System (MCS 3.2), delivering peak charging rates of 1.2 MW. At that rate, the Long Range recovers approximately 60% of its battery capacity in 30 minutes — roughly 300 additional miles of payload-carrying range per stop.
Tesla has been building dedicated Megacharger infrastructure ahead of Semi deliveries. A facility being expanded in Firebaugh, California, on Interstate 5, will feature 16 Megacharger stalls specifically for Semi operations alongside a major passenger Supercharger expansion. Tesla Semi Program Manager Dan Priestley noted the site's strategic value directly: "Lots of trucks to electrify on I-5."
The MCS connector is not compatible with standard CCS or NACS passenger vehicle connectors, requiring Tesla to build a parallel charging infrastructure specifically for fleet operations alongside its existing Supercharger network.
The Total Cost of Ownership Case
At 1.7 kWh per mile, the Semi's energy cost per mile depends almost entirely on commercial electricity rates. At the U.S. commercial average of roughly $0.12 per kWh, that works out to approximately $0.20 per mile in energy costs — compared to diesel trucks averaging $0.35–$0.45 per mile at current diesel prices. The savings widen as diesel prices rise and narrow as electricity costs increase.
For fleet operators running high-mileage routes within the 500-mile range boundary, the Long Range Semi's total cost of ownership case is straightforward. The Standard Range at 548 kWh and 325 miles targets regional distribution routes where a lower purchase price and shorter distances create better economics than the long-haul variant.
The Bottom Line for Electric Trucking
The CARB certification settles the most debated specification in electric trucking: how much battery the production Semi actually carries. The answer — 822 kWh and 548 kWh — is lower than prototype estimates but sufficient to meet the stated range targets. High-volume manufacturing has officially begun. The question that remains is how quickly Tesla can scale production at Giga Nevada to meaningful delivery volumes, and whether the Megacharger network expands fast enough to serve a growing fleet.
Photo: Tesla industrial facility / Pexels