Details on Tesla’s First $35,000 Mobile Supercharging Station


“The Bethesda Supercharger is a Mobile Supercharging Unit designed to support customers while we complete construction of an 8-stall permanent Supercharger location in Woodbridge, Virginia opening soon.”

Says Tesla Motors.

However, we sense that this particular 2-stall Supercharger will stay put even after that “8-stall permanent Supercharger location in Woodbridge, Virgini” comes online.  Tesla’s cost for this Mobile Supercharger is only $35,000.

Bethesda Supercharger Now Open!

Bethesda Supercharger Info

Bethesda Supercharger Info

  • Bethesda Supercharger
  • 7101 Democracy Blvd, Bethesda, MD 20817
  • 24 hrs/day
  • Charging Stalls – 2

What’s unique to this Bethesda Supercharger is its mobility.  From the image, you can clearly see where a fork lift could pick up the Supercharger for movement to a new location.  This would allow Tesla to temporarily place Superchargers where needed.  For example, if Tesla hosts a racing event, a few mobile Superchargers could be placed track side.  Or if there’s a BIG Model S meet up, Tesla could get a few of these units on site.  Additionally, we think you’ll start to see more and more of these chargers at Tesla’s various stores and service centers.

Yes, we fully understand that the electrical would need to be in place for the unit to be functional.

Notice the B?  If You Want to Guarantee Full Juice, You'd Want to Make Sure That a Model S Wasn't Plugged Into the 182A Supercharger

Notice the B? If You Want to Guarantee Full Juice, You’d Want to Make Sure That a Model S Wasn’t Plugged Into the 182A Supercharger

Finally, there’s been some inaccurate rumors flying around the web lately suggesting that Tesla has patented some sort of “new” type of Supercharger that splits power among the various Model S EVs that are plugged in.  Those patents are years old and Tesla’s Supercharger have always been power splitters.  Here’s a basic rundown of how a typical Tesla Supercharger operates:

  • Each Supercharger cabinet supports two plugs, but can only deliver ~120 kW total.
  • If two Model S EVs are plugged into shared cabinets, then the loads get split (the power splits are complicated stuff, so we won’t go into detail on how it all works out).
  • At a Supercharger, plugs are listed 1A / 2A / 3A / 4A / 1B / 2B / 3B / 4B and so on.
  • 1A shares a cabinet and power with 1B.  2A shares with 2B and so on.
  • If you want/need access to the full 120 kW of power, try not to park in a spot that is sharing with another plugged in Model S.

Obviously, in Bethesda, where there’s only two charging stalls, the power is split between the two points when a pair of Model S EVs are charging up, so you can’t avoid the lower power charge there when another Model S is grabbing some electrons.

Categories: Charging, Tesla


Leave a Reply

11 Comments on "Details on Tesla’s First $35,000 Mobile Supercharging Station"

newest oldest most voted

Re: “If you want/need access to the full 120 kW of power, try not to park in a spot that is sharing with another plugged in Model S.” — seems like the car should suggest which one at a particular site you just drove up to is the optimal one to plug into. Must have been discussed before since it is so obvious.

My comment was meant to imply look at more than an empty A/B combos. I think if several are full then the car (via supercharger mothership) would know which cars are tapering down and thus would open up the corresponding A or B plug where you could get the 90+ kW charging. The car would suggest the best spot based on all considerations and your charging needs (how long you need/want to charge)

It’s more complex than that. You also need to know the charge state of the cars in the other slots (if one is at the end of a charge, there is plenty of spare power for your car on the companion connector).

Yes, this would be a wonderful bit of technology but I’d put it at the bottom of the wish list for the understaffed Tesla software team. There are lots of other things that I (and other owners) would prefer to see first. Like better google maps integration, waze support, pandora (drop kick slacker to the curb)…

How about displays on the chargers showing time remaining, or colored light indicators for “Best, Good, OK, Worst”?

Don’t think it matters picking ‘A’ vs. ‘B’ stall first … just that kWatts will be shared if another Model S is charging from the same charger number. A speed difference will be more noticable at low SOC, but will decrease when charging from a higher SOC (when charging amps decrease anyway).

Ideal would be if a supercharger app indicated the most ideal spots or even better gave available KW and approximate completion times. Maybe allow users to set their miles desired and time to charge in the future.

Looks like Denver will receive mobile chargers too. Perhaps it is cheaper to go this route vs. blowing up concrete.


These mobile superchargers are especially good if they are equipped with about 200–500 kWh storage battery. This way they can be integrated into local solar systems and more importantly they are good with much lighter grid connection.

And this of course means that there will be millions of superchargers all around the globe!

Interesting idea… As it is, this skid mounted SC needs a (in the states) 200 amp 277Y/480 volt (or 400 amp 120Y208 volt) ‘roadshow’ hookup.

Be interesting to see if that disconnect switch is really a 600 volt 400 amp unit so that they can switch on the fly – hook up to either 208 or 480 volt facilities commonly available in the states. 347Y/600 operation is not possible so for Canadians the only alternative is to also drag along a 600-480 volt autotransformer, or else insist that the connection be 400 amps 208 volts. Too bad we don’t have the details.

@JV, I’d hate to rain on your parade, but even at a mere 100k$ a pop (which may not even pay for the battery you suggest, let alone solar to power the thing, but let’s not get those details get in the way), your just-so-slightly optimistic number of superchargers would come with a modest 100 billions$ pricetag…

Pocket change for the DoD maybe, but not for any company, and in particular Tesla, which, given its closed system, is unlikely to get help from anyone.

To put this in perspective, it takes four major automakers plus government subsidies to pay for “””only””” (yes, that was 3 pairs of quotes) 36’000 QCs…