2013 Tesla Model S: How Much Range Is Lost When Parked?
February 28, 2014
One of the frequently asked questions I get about electric vehicles goes like this: "What happens to the battery when the car sits parked? How many miles does is lose just sitting there?"
OK, that was two questions, but still.
A couple of weeks ago I deliberately checked out the 2013 Tesla Model S for a trip I took to Puerto Rico to test the upcoming 2014 Mini Cooper.
The Model S was my ride to the airport, and it sat idle in an LAX parking structure for three days while I flew south for the winter. Tesla's handy iPhone app confirmed it had 204 miles of range as I boarded the Wally Park airport shuttle.
How much would it have when I came back?
I took periodic screen captures of the Tesla iPhone app at random intervals during my trip. After an uneventful red-eye flight out of Los Angeles, I recorded the first couple during the 14 hours I was stranded at the Atlanta airport as my connecting flight was cancelled not once, but twice. I took another when I finally checked into my Puerto Rico hotel room at 2:39 a.m. the next morning.
Each check-in took a couple of minutes while the car woke up at the prompting of the app. This delay is a symptom of the new power-saving feature that entered the picture last December as part of software update v5.8.
There was no such delay before the power-saving feature was added. A certain part of the car's brain was booted up and alert all the time, and that apparently came at the cost of a certain amount of battery drain and loss of range.
I returned to the car about one hour shy of three days later. In that time the range had dropped from 204 to 200 miles, not very much, if you ask me. A drain of a mile-and-a-bit per day seems entirely satisfactory to me.
But why was there any drain at all? I suspect it's because the car still has to be semi-conscious so it can respond to a wake-up call from the app. In such circumstances zero drain doesn't seem possible. And of course the car awoke from its slumber each time I pinged it before going back to sleep.
Interestingly, this new power save feature has an off switch that removes the delay and reinstates the pre-update alertness our car had before December.
I have another business trip coming up. Perhaps I'll drive the Tesla to the airport once more and leave it there for a few days with the power save feature turned off to see what kind of difference this setting makes.
Dan Edmunds, Director of Vehicle Testing @ 18,523 miles