Tesla’s maiden battery-swapping station was slated to open weeks ago. But it doesn’t appear that the facility is quite ready for business.

According to a tweet Tesla CEO Elon Musk posted, the station was operating mid-December in “limited Beta mode.” Swapping a battery at the station was to be by invitation and appointment only, with offers sent to a select but undisclosed number of Model S owners. However, as of this week the station still wasn’t open.

The Harris Ranch station in Coaling, Calif., is adjacent to a Supercharger that’s already operational. Its Southern California location is conveniently located for travelers driving between Los Angeles and San Francisco, providing a quick-stop option that’s faster than a recharged. The building is a converted car wash, with one bay open for battery swapping.

On Jan. 6, Tesla owner LeeAnn Fick posted photos of Harris Ranch on her blog and noted that the station was still under construction.

“There were workers putting tar sealer on the entrance and exit paving, so it looks close to beta testing,” said Flick on CrossCountryTesla.blogspot.com. “This location has very limited size and therefore storage capacity – couldn’t handle much volume.”

A follow-up visit by Katie Fehrenbacher with Gigaom.com this week revealed that more than a month after Musk’s tweet, the station still isn’t operational.

“My assessment? It looks like Tesla’s first battery swap station at Harris Ranch is close to being finished. On my visit, I could see that the battery swapping compartment in the ground of the station was constructed and the station’s signs were in place.”

Her photos of Harris Ranch include a shot of the simple single bay, with construction materials cluttering the floor.

Though the facility will only be able to service one car at a time, Tesla estimates that it will take only a few minutes for the robotic arm to remove the old battery and replace it with a new, freshly charged pack.

“At least initially, battery swap will be available by appointment and will cost slightly less than a full tank of gasoline for a premium sedan,” said the Tesla Motors Team in a blog post. “More time is needed to remove the titanium and hardened aluminum ballistic plates that now shield the battery pack, so the swap process takes approximately three minutes. With further automation and refinements on the vehicle side, we are confident that the swap time could be reduced to less than one minute, even with shields.”

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Since the initial December 19 announcement, Tesla hasn’t released an update on the battery swap station, which leaves some concerns unanswered.

“While the swapping tech isn’t rocket science, the business model and the battery swapping pricing could be more difficult to figure out,” said Fehrenbacher. “Customers could pay $50 to $60 for a battery swap, and then either pick up the fully charged battery on the way back, pay extra to have the battery shipped to them, or pay the difference in the lifespan of their battery compared to the new one.”