The arrival of modern electric cars and public charging infrastructure has brought a whole range of etiquette issues to the fore.
Electric cars' long charging times, and the limited availability of parking spaces with access to charging stations, can sometimes create a bit of tension.
It's not unheard of for drivers to unplug other cars when they can't find a charging station of their own--whether those cars are done charging or not.
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There's been much discussion about what to do in these situations, but now there's a simple solution.
The signs are shaped like the "Do Not Disturb" signs you'll find in hotels, and they slip over a standard J1772 charging connector.
There's even space on the "Do Not Unplug" side in which the driver can write the time when a car will be finished charging, along with a phone number.
Both sides of the card also have a list of charging-etiquette tips that should encourage peaceful relations with other drivers.
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They advise electric-car owners not to park in a charging space if they aren't actually charging, to limit their charging times, and--of course--never to unplug another car while it's charging.
One more feature is a QR code which, along with a link to the Take Charge and Go website, provides further information on public charging.
The signs are available through Take Charge and Go individually for $2.49 each, or in a 10-pack for $19.99.
Note that some electric cars have locking mechanisms that prevent them from being unplugged until charging is complete--unless the key fob is nearby.
Only some plug-in cars have this feature, but it could create a minor sticking point in an otherwise straightforward system of owners giving permission to unplug after a certain time or charge level is reached.