The California Air Resources Board has validated Tesla Semi’s battery capacities, showing the Long Range variant at 822 kWh and the Standard Range at 548 kWh. These sizes are less than Elon Musk's original projection but showcase efficiency gains enabling Tesla to maintain its touted 500-mile range at full load.
- Long Range pack size cut about 80 kWh from original estimates
- Standard Range targets regional haul with 325-mile range
- Tri-motor drivetrain supports fast 1.2 MW Megacharging
What happened
The California Air Resources Board (CARB) formally confirmed the battery capacities for Tesla’s Semi truck through its Executive Order A-374-0095, signed on April 15, 2026. According to the filing, the Long Range Semi uses an 822 kWh usable battery pack, while the Standard Range model has a 548 kWh pack. Both versions utilize Tesla's latest NCMA lithium-ion chemistry and 4680 cells.
This official data contrasts with Elon Musk’s 2022 statements that estimated the Long Range battery at around 900 kWh based on a 1.7 kWh-per-mile consumption target for a 500-mile range. The smaller official battery size reflects efficiency advancements, including a nearly 1,000-pound weight reduction in the production Semi revealed in March 2026.
Why it matters
The confirmed battery sizes underscore Tesla’s edge in electric Class 8 trucking efficiency and cost-effectiveness. At 1.7 kWh per mile, Tesla’s Semi outperforms competitors delivering roughly 0.4 to 0.5 miles per kWh. This stems from aerodynamic enhancements, a highly efficient tri-motor powertrain, and weight savings from the refreshed design.
Economically, this translates to significant savings for fleet operators. Tesla estimates energy costs near $0.20 per mile at $0.12 per kWh electricity rates—substantially lower than diesel trucks operating at roughly $0.67 per mile. Over a decade, this could save more than $400,000 in operating costs, accelerating the total cost of ownership benefits for commercial trucking.
What to watch next
Attention will focus on Tesla’s Standard Range model priced around $260,000, which offers a 325-mile range covering most regional haul use cases. This more affordable option drops one battery module from the Long Range pack, conserving weight and materials and catering to varied operator needs.
The growth of Tesla’s Megacharger network—currently 66 locations across 15 states—and its 1.2 MW charging capability will also be pivotal. The Long Range Semi’s ability to regain 60% charge in 30 minutes supports regulatory driver rest breaks, enhancing operational efficiency and trucking route planning.