The 1-MW Tesla Semi Charger Will Roll Out As the Supercharger V4, Here's How It Works

The Tesla Semi took center stage at its first delivery event on Thursday, which was expected. Nevertheless, Tesla officials, Elon Musk included, could not keep their lips tight about other products either related to the Semi or not. In the first category, Musk revealed interesting details about the megawatt charger used to fast charge the Class 8 truck. In the latter, we also learned new things about the upcoming Cybertruck.

But first things first: the huge battery packs of the Semi require an equally monstrous charging system to top them up in a reasonable time. We knew that already and, based on Musk’s claims about the Semi, speculated that the chargers should be able to pump out 1 MW of power, which was unprecedented. Nevertheless, it seems that Tesla was dead-serious about the performance of its Semi charger.

More than that, the new Tesla Megachargers will turn into the V4 Supercharger poles expected to replace the current-generation chargers starting next year. This is interesting because previous rumors indicated that Tesla would go separate ways with its Semi chargers and the Supercharger network. Previously, the V4 Supercharger was expected to deliver 500 kW of power over a 900-volt connection or to charge two V3-compatible vehicles with 250 kW simultaneously.

During the Tesla Semi delivery event, Elon Musk confirmed that the megawatt charger used by Tesla Semi would roll out to every Supercharger station in the future as the Supercharger V4. The first passenger vehicle capable of using the full power of the V4 Superchargers will be the Cybertruck. This all but confirms that the Cybertruck will have a 900-volt electrical system. Moreover, the cable and the plug connector will remain unchanged, thanks to clever engineering solutions that keep the temperatures down.

According to Elon Musk and Dan Priestley, who is Tesla’s Senior Manager of Semi Truck Engineering, Tesla used immersive-cooling technology, with the high-voltage conductors immersed in cooling liquid. This allowed Tesla to triple the current density over the existing cable instead of using “a giant elephant trunk of a cable,” as Musk said.

“We’re actually immersing the conductors in the coolant,” explained Priestley. “It means that we can really shove a lot of current in a very, very small place. So for those who have charged their cars at a V3 Supercharger and the cable’s nice and maneuverable, it’s the same thing here, but now we’re just shoving a megawatt through it instead.”

Delivering 1 MW of power over the same connector used for Tesla passenger cars makes a strong point for the plug that Tesla wants to make standard across North America. Recently, Tesla open-sourced its connector in a bid to replace the cumbersome CCS plug as the standard connector, at least in the U.S.