Unusually, I had an appointment over on Park St in Alameda (the main shopping street in our little island city), and a couple of conference calls before it. I got to the Civic Center parking garage around 9am and found the working Chargepoint available. [The garage has two chargers, each offering a level 1 and a level 2 connection. One has been out of order for months now, but that’s another story.] There was a Chevy Volt parked in one of the spaces next to the working unit, but, oddly, it was not plugged in.

Surprised by my luck, I plugged in and activated the charger using my NFC card; checked charging had started, and headed off to the Local, the café on Park Street where my 11am meeting was to happen.

I checked the status of the charging from my watch around the start of my first meeting and it showed that it was working. Pre-occupied with calls, I didn’t get a chance to check again until just before my 11am meeting. When I checked, I was surprised to see that charging had stopped and I’d only gained a few percent on the charge level.


Around 11:45am, I got back to the car only to find that the car next to me had unplugged the cable and plugged in their own car. I still had an hour left on my parking (it is pre-paid in that lot), so I thought I’d plug in my level 1 charger and at least get some charge (I’m not mean enough to unplug somebody else, even when they’d done that to me).

Here’s where things get strange. To unlock the door for the L1 port you need to tag the machine with the card. When I did that, the charger asked me whether I wanted to end the current session. Well, no. What I wanted to do was unlock the door, but then it occurred to me that even though the cable had been moved from one car to another, it appeared that the charger still thought that was my session (luckily these are free). Nothing I could do would make it unlock the L1 door while the other car was plugged in. I even tried to use my phone to unlock it, but that didn’t work either.

Locking Cables or Session Locking

This has been a topic of discussion a few times on Twitter, and while some people have indicated that their chargers and/or cars lock the cable to the car during charging, it certainly isn’t the case with any I’ve used here. It is very simple to just walk up to the car an unplug the cable. And, it seems, quite possible to just move it to another car.

The most obvious ways I can see to solve this are:

  • Have the connector lock onto the car automatically
  • Add some software protection that prevents a new session until the previous one has been explicitly ended (this has some obvious problems too!)
  • Add a way for the user to lock the connector themselves (e.g. a place to attach a padlock that prevents the disconnect button from being pressed)

Of course, car manufacturers could also include locks that prevent the cable being unplugged (I’ve heard that some might do this already). It looks as though as EVs become more common, and the demand for the limited number of charging stations increases, measures like this might become necessary, however sad that may be.

Be the first to comment

Leave a Reply

Your email address will not be published.