2013 Fiat 500e live photos, 2012 L.A. Auto ShowEnlarge Photo
It's a standard fitting on most plug-in electric cars: a visible light to show when it's recharging, often with a different indicator for when it's done.
Those lights, often on top of the dashboard and visible through the windshield, aren't yet standardized.
They come in red, orange, and green; some flash, some are solid.
And some other plug-in cars--the Tesla Model S and Ford Focus Electric among them--have a ring of colored lights around the charge port itself, rather than on the dash.
Now the low-volume 2014 Fiat 500e has a new wrinkle: an externally visible state-of-charge indicator that shows the battery's percent of charge.
It's similar to information that's available to owners on most plug-ins' touchscreen displays, often via a smartphone app for the car as well.
The low-volume Honda Fit EV also shows state of charge on a tiny display built into the car's remote control key fob.
Turns out, though, that not every electric car owner thinks the Fiat 500e approach is a good idea.
Tom Moloughney, who now drives a BMW ActiveE and previously had a Mini E, wrote:
I don't like the outside state-of-charge indicators, and don't want one on my car. I think a snappy smartphone app (I mean it works and it's instant!) would be all I need. I don't want others walking by knowing my SOC.
I can imagine it will lead to people unplugging you because they "really needed to charge badly and saw that you were almost full anyway."
I don't mind so much if the state of charge is shown somewhere inside the car, so you can quickly look inside and see it--but I definitely don't want something outside the car like what this pic shows. No way!
Honda Fit EV electric car remote-control key fob showing battery state of chargeEnlarge Photo
"I think an external indicator that only shows if it is complete could be useful," suggested ActiveE driver Jon Jasperson, adding, "otherwise I do see a lot of charges getting interrupted."
Other owners, though, weighed in to disagree, saying that external lights were useful and appropriate in a large number of situations--and that they'd never experienced anyone unplugging their electric cars during a charge.
What do you think?
Should electric cars show their battery state of charge to the public at large?
Should they show only a light when the charging is complete?
Or is battery state of charge no one's business but the owner's?
Lave us your thoughts in the Comments below.