A jubilant team of Tesla employees celebrated their record-breaking cross-country road trip at the Manhattan Tesla Store last Sunday.
And for having spent 76 hours either driving a Tesla Model S electric car across the country or sleeping in a support van, they looked pretty good.
The trip demonstrated the ability of an 85-kilowatt-hour Tesla Model S to cross the country in about the same time as an internal-combustion-engine car, at zero cost to recharge. The drivers were Tesla employees who have been involved in the development of the Supercharger network.
The celebrations at the finish included a question-and-answer session with the drivers, along with JB Straubel, a cofounder of Tesla Motors and its longtime chief technical officer.
Interesting details about the trip emerged from the event, including the following.
Notes from the road
Since it was a company-sponsored event, the team drove at the legal speed limit the entire way. This was no Cannonball run, which means it left an opening for others to attempt and break the record for an all-electric cross-country journey by those who don't mind risking a ticket.
The longest leg of the trip was an unintended 265-mile stint, owing to a road closure along I-70 due to winter weather. Even then, the drivers said, they didn't have to drive below the speed limit to conserve energy.
The only times they reduced their speeds were for safety reasons, in the middle of a blizzard or sand storm.
Drivers kept the battery at a low state of charge as much as possible without too much risk. This allowed them to use the Superchargers at their full potential.
Since charge rates decrease as the battery charges up, they tried to pull into the Supercharger stations with no more than 10 to 15 miles of range remaining--and only recharged enough to get to the next supercharger.
At this event, they said the average energy use for both cars was between 350 and 360 Watt-hours per mile; the numbers on the Tesla Motors blog calculates to 346Wh/mi, which is even more efficient.
Reception at Tesla Store in New York Ciy following cross-country road trip in Model S electric carsEnlarge Photo
Snow and regenerative braking
One driver who braved one of several snowstorms in Colorado mentioned that the car drove impeccably in the snow, but having strong regenerative braking would sometimes cause the tires to come loose from the road.
He experimented with taking his foot off the accelerator pedal more carefully, but ultimately chose to use a less aggressive regenerative-braking profile--which he was able to set on the car's in-dash display screen.
One of the two support vans broke down on the journey. That gave the entire journey an ironic twist to the story, in which electric vehicles crossed the country with no problems, but the engine vehicles supporting them via internal-combustion engines had mechanical trouble.
The drivers had not intended to complete their trip and arrive in New York City on Super Bowl Sunday, with the game being hosted in nearby East Rutherford, New Jersey.
The Supercharger network is a high priority for Tesla in 2014, and the company intends to continue opening new locaitons at a rapid pace. It has a goal of 100 miles between stations.
Superchargers can recharge a Tesla Model S at 120 kilowatts, compared to 30 to 50 kW at ChaDeMo chargers or 6.7 kW at most 240-Volt Level 2 charging stations.
For Tesla, battery swapping is not as high a priority as the Supercharger network. The company is collecting data on the potential use of that technology before dedicating resources to the project.
Elon Musk had greeted the team as it pulled in, to congratulate them on their successful journey.
But by the time of the public event, he was said to be driving his kids around in one of the cars after its journey to show them New York City