As we reported earlier this week, a Tesla Semi prototype is traveling around the US – apparently visiting several reservation holders.

The electric truck stopped at a Supercharger in Colorado where Tesla Semi engineers talked about how they charge the electric truck at a Supercharger.

Over the past two weeks, a Tesla Semi prototype drove to J.B. Hunt in Arkansas almost 2,000 miles away from its home base and then to UPS’ hub in Addison in Illinois, which is about 600 miles north from J.B. Hunt in Arkansas.

Earlier this week, we reported that the Tesla Semi prototype was now in Des Moines, Iowa – more than 300 miles from UPS.

Yesterday, the electric truck prototype traveled another 580 miles or so and stopped at Tesla’s Supercharger station in Brush, Colorado.

Electrek reader Erik J. Martin was there to welcome the truck when it arrived last evening:

He said that Tesla engineers arrived ahead of the Tesla Semi to reserve the Supercharger stalls and arrange the setup to charge the electric truck.

Tesla CEO Elon Musk said that Tesla Semi made it ‘across the country alone’ with only Supercharger network and an extension cord.

Musk jokingly added that they used a 1,000-mile long extension cord, but he is actually referring to a system made of extension cords that they have used to charge Tesla Semi prototypes at Tesla’s regular charging stations.

Tesla Semi is supposed to eventually used its own network of ‘Megachargers’, which can enable a higher charge rate than the Superchargers, but those new stations have yet to be deployed.

People who have witnessed Tesla Semi prototypes charging at Supercharger stations have told Electrek that the system made of extension cords plugs into several Supercharger stalls at the same time and into several charge ports on the truck.

Weirdly, Martin said that engineers insisted that no one take pictures or videos of the system.

He also learned a few interesting details from those engineers – mainly that this specific prototype is configured for a 300-mile range.

After Tesla revealed the pricing of its electric semi trucks last year, we learned that the regular production versions for the 300-mile and 500-mile range versions will be $150,000 and $180,000 respectively, while the company is also listing a ‘Founders Series’ version for $200,000.

Martin also said that engineers told him the prototype was equipped with 26 cameras, but the production version will have fewer. In comparison, the latest Autopilot hardware suite on Tesla’s passenger cars has only 9 cameras.

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