Eighteen months ago, in the kind of flashy, highly-publicized event it's so good at, Tesla Motors said it would launch battery swapping for its Model S electric car.

CEO Elon Musk presided over a demonstration in which the underfloor battery pack of a Model S was apparently removed and replaced in roughly 90 seconds.

A trial location for a single swapping station was finally announced in November, at one Supercharger location; it will require Model S owners to make an appointment for a swap in advance.

DON'T MISS: Tesla Battery-Swap Pilot Program To Launch Next Week In California

In late December, Tesla fan site Teslarati visited the prototype swapping station.

Ironically, it's located behind a Shell gas station in what appears to be a former car wash, across the street from a large Supercharger quick-charging facility.

Teslarati included several photos of the installation, which at that point looked close to being ready.

Photo of Tesla Model S battery swapping versus 'fastest gas pump in LA' tweeted by Elon Musk

Photo of Tesla Model S battery swapping versus 'fastest gas pump in LA' tweeted by Elon Musk

Now we have an update from the enterprising Katie Fehrenbacher of GigaOm, who drove down to the site last week and took her own photos of the Harris Ranch swap station.

She too suggests that the site appears to be almost ready for use.

The station currently consists of a single swapping bay, along with a second bay that's presumably for deliveries.

MORE: Tesla Shows 90-Second Battery Swapping For Model S, Details Rollout Plans (Jun 2013)

The Tesla Model S was designed from the start to enable swapping, which has the added benefit of making battery installation easier on the assembly line in Tesla's factory in Fremont, California.

But it's not clear how much consumer demand exists for battery swapping.

Tesla's Supercharger DC quick-charging is free to all Model S owners whose cars have the capability, which takes 20 to 30 minutes to recharge the car's battery to 80 percent of capacity.

Tesla Model S P85D, 2015 Detroit Auto Show

Tesla Model S P85D, 2015 Detroit Auto Show

To swap for a fully-charged pack, however, Tesla owners will have to pay a fee--not yet specified, but thought be $50 to $60--to reduce their "recharge" time to a few minutes.

The only other major implementation of battery swapping was built by now-bankrupt Israeli electric-car service Better Place. Those stations are now all defunct.

The test site isn't expected to offer the same, fully automated 90-second swapping shown off by Musk in June 2013. Instead, it will likely involve a combination of automated and manual steps by on-site staff.

Much speculation has centered around the reasons Tesla pledged to offer pack swapping.

Better Place Battery Swapping

Better Place Battery Swapping

Many of the suggestions note that Tesla receives a higher number of credits for sales of its zero-emission vehicles from the California Air Resources Board (CARB) if the vehicle can "refuel" at the same rate as a gasoline vehicle for roughly similar range.

Sometime soon, one or more Tesla owners will be able to get that experience first-hand--after making their appointment beforehand.

For complete photos of what the swapping site actually looks like, visit the Teslarati and GigaOm photo galleries linked above.


Follow GreenCarReports on Facebook, Twitter, and Google+.