Tesla has released a new video showing a Tesla Semi truck charging at a massive 1.2 megawatts (MW), finally giving us a clear look at the charging speeds that will enable long-haul electric trucking.
For years, we have been waiting to see the “Megacharger” in action. While Tesla has delivered Semi trucks to partners like PepsiCo, who have been using them for real-world routes, detailed data on the charging performance has been somewhat scarce.
We knew the target: Tesla claimed the Semi would be able to charge 70% of its range in 30 minutes. For a truck with a 500-mile range and an estimated battery pack of around 800-900 kWh, that requires an incredibly high power output, well beyond the 250 kW or even 350 kW we see on passenger EVs in North America.
Today, the official Tesla Semi account on X released a video showing exactly that.
In the video, Tesla engineers are seen monitoring a charging session where the power output climbs to a peak of 1.2 MW (1,206 kW):
This is consistent with the capabilities Tesla announced for its new V4 Cabinet architecture earlier this year. The V4 cabinets are designed to support 400V-1000V vehicle architectures and can deliver up to 500 kW for cars (like the Cybertruck) and up to 1.2 MW for the Semi.
There is some information missing from the video. For example, we don’t see the state-of-charge of the truck, so we don’t at what battery percentage Tesla Semi can achieve and maintain this charge rate.
Peak speed is one thing, but sustaining that power without overheating the pack or the cable is the real challenge. The liquid-cooled charging cable and the immersion-cooled connector (part of the Megawatt Charging System or a high-power proprietary Tesla solution, though Tesla has been leaning toward MCS compatibility) seem to be doing their job.
At 1.2 MW, you are adding approximately 20 kWh of energy every minute. If the Semi indeed has an ~850 kWh pack (based on the 1.7 kWh/mile efficiency rating Tesla has touted), this charging speed theoretically allows a 10-80% charge in under 45 minutes, provided the curve doesn’t taper too aggressively.
This comes just as Tesla is gearing up for volume production of the Semi at its new factory expansion near Gigafactory Nevada. The automaker is targeting a start of production in the first half of 2026 and a ramp up to volume production in the second half.
Author: Fred Lambert
Source: Electrek
Reviewed By: Editorial Team
