New images from Giga Nevada suggest that Tesla may be looking to develop a mobile “Megacharger” system for the upcoming Class 8 all-electric Semi. The system seems to be powered by Powerpack batteries.
To clarify, the “Megacharger” is the name of the Semi’s charging infrastructure, as mentioned by CEO Elon Musk during the vehicle’s unveiling in late 2017. Pictures shared with Teslarati show Tesla’s progress with the buildout of Megachargers at Giga Nevada–and maybe a little more. There are a least two Megachargers at the Gigafactory, and Tesla might install more in the future, especially as the Semi’s limited production starts rolling.
However, right behind the Megachargers is a trailer with four Tesla Powerpacks and two urban charger stalls. According to Teslarati’s source, there were two trailers at Giga Nevada, and one of the trailers was fitted with Tesla Powerpacks, which may hint at a potential portable charging system.
Tesla’s Mobile Charger Solutions
Tesla has deployed mobile EV charging systems in the past. In 2019, Tesla deployed mobile Superchargers powered by Megapacks for the holidays. It was a simple and practical solution to increase the number of charger stalls at select Supercharger stations quickly and efficiently. Reports then indicated that the Megapack-powered mobile Superchargers could charge about 60-100 vehicles thanks to the Megapack’s 3 MWh capacity.
Mobile “Megachargers” would be a practical move for Tesla and the Semi’s clients. Mobile “Megachargers” could help top-up Semis in popular transport routes while Tesla concentrates on growing its Supercharger Network and the Semi’s dedicated charging infrastructure. Mobile “Megachargers” could also be a cost-effective way for Tesla and the Semi’s clients to ensure that chargers are present for the Class 8 electric truck in locations where they are needed the most.
The Semi’s “Megacharger” Evolution
In 2018, a Tesla Semi prototype sighted in Des Moines, IA was spotted using an ad hoc “Megacharger” system that utilized 5 Supercharger V2 stalls. By 2020, sightings of the electric Class-8 revealed an updated ad hoc “Megacharger” solution that used only 2 Supercharger stalls. It was unknown whether the two stalls charging the Semi in 2020 were V2 or V3 Superchargers.
The trailer in the picture recently shared with Teslarati held two urban chargers, suggesting a potentially similar charging setup as the Semi prototype spotted in 2020. As for the use of Powerpacks instead of larger Megapacks, it might be down to cost.
According to Elon Musk during a 2021 interview with noted podcast host Joe Rogan, the Semi’s 300-mile variant should be equipped with a battery pack that’s around 500 kWh. Previous estimates suggested that the Semi will be fitted with a 600 kWh battery pack for the 300-mile version and a 1 MWh battery pack for the 500-mile Semi variant.
One Megapack has a capacity of 3 MWh and costs about $1.2 million as of July 2021, when Tesla updated the Megapack’s order page. A single Megapack could potentially charge several Semis consecutively, but the costs for such a solution would be substantial. Considering that one Tesla Powerpack has a capacity of up to 232 kWh, four units of the commercial-grade battery would likely have about ~900 kWh of energy capacity. This would likely be enough to top up a couple of Semis at a time, without requiring the full costs of a Megapack-powered system.