Until now, Tesla has revealed almost no details about the actual operation of the charging infrastructure for the Semi. Although electric trucks have already been delivered to partners, including PepsiCo, and used on commercial routes, data on charging speed and characteristics remained limited. Previously, Tesla only stated that the Semi would be able to replenish up to 70% of its range in about 30 minutes.
The published video appeared on the official Tesla Semi account on the social network X. In it, company engineers observe the charging process, during which the output power reaches a peak value of 1.2 MW, or 1206 kW. These figures match the capabilities of the new Tesla V4 charging architecture, presented earlier this year.
Engineers hitting 1.2MW on Semi Megacharger pic.twitter.com/QtXyTgW0XC
— Tesla Semi (@tesla_semi) December 31, 2025
The V4 charging systems are designed to work with vehicles with a voltage of 400 to 1000 volts. For passenger models, including the Cybertruck, they can deliver up to 500 kW, and for the Tesla Semi — up to 1.2 MW.
However, some key data is missing from the video. Tesla does not disclose the battery charge level at the time of reaching peak power, so it is unknown at what battery percentage the Semi can reach such values and how long it maintains them. Maintaining high power without overheating the battery and cable remains one of the main technical challenges.
At a power of 1.2 MW, about 20 kWh of energy enters the battery per minute. If the Tesla Semi battery has a capacity of about 850 kWh, then theoretically charging from 10 to 80% can take less than 45 minutes.
Tesla is currently expanding the factory in Nevada to begin truck production in the first half of 2026, with a subsequent move to mass volumes in the second half of the year.
Source: Electrek
