Tesla Model S "Sleep" Mode Still Draining Batteries?


nolands-model-sA Tesla Model S owner, David Noland, said that the vehicle consumes a considerable amount of electricity even when it is not in use, and that it reduces the range of the vehicle by 23 miles per day. Turns out this is because of the same software issue we heard of in the past, which Tesla Motors supposedly addressed with a software update.

The issue was that the vehicle’s on-board electronics were still on, and they stayed on all the time. This drained the battery at an impressive clip, especially in sub-freezing temperatures. The loss of mileage was quite substantial, according to Noland.

In a post on Green Car Reports, he said that he first noticed this when his electricity meter appeared to be running faster than usual. He has the Tesla Model S equipped with a 60 kWh battery bank. He unplugged the vehicle at 9 PM when the range was 169 miles, and the following morning, the range had decreased by 16 miles to 153.

He proceeded to unplug the Tesla Model S again the following night, and the range decreased from 89 miles to 66 miles, which is a 23 mile decrease. There were two more tests that confirmed the pattern of range loss. He lost roughly 1 mile for every hour the vehicle was unplugged, and Noland said that the vehicle was using as more energy than he normally used to drive daily, so this really is significant.

The software update to address the issue is supposed to be available by July, and will bring vampiric electricity loss down to just 0.2% per day. But Noland still found that he seemed to be losing about twice as much mileage as the official Tesla line. He found that, even when plugged in, his car would go through about 4.5 kWh of power in 18 to 24 hours. That is a lot of lost power.

Is this just one owner’s bad luck, or the tip of a larger problem?

Source: Green Car Reports | Image: David Noland

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About the Author

loves attending and writing about/photographing events, and he writes on CleanTechnica, Gas2, Kleef&Co, and Green Building Elements. He has a keen interest in physics-intensive topics such as electricity generation, automobiles, refrigeration and air conditioning technology, energy storage, and geography.

  • Javier

    O.k. Good ..

  • PorfirioR

    I have seen pieces of David’s blog post recycled and splattered all over the internet with various attention-grabbing headlines. In the same post David also admitted that he leaves his keyfob inside the car overnight. Unlike a Prius or other EVs, Tesla’s key, when within proximity of the car, does a little more than “let” you turn on the car, it DOES turn on the car.

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  • Sounds like a lot of power just for computers. For instance an idling powerful Ivy Bridge laptop only takes about 20 watts constantly. I doubt a Tesla Model s has more computing power than that. So that’s 0.480KW hours a day. So my guess is that the battery thermal management system is very aggressive even with the car unplugged and key fob no where near it and with the key fob still in it it is even worse?

    Time to release a patch!

  • Michels

    Noland tops off the last 1% and adds up the energy it takes to charge then says his car will run dead by his horrible math in 13 days. Topping off a battery produces alot of heat and very little goes it to the battery. Then he says the car uses x energy because it took that much to top off. He says he’s smart, but think charging works like filling a gas tank. I wish this idiot wout just leave his car unplugged for 13 days. and then charge it much easier to get a good number that way.

  • I wonder if the mice will go in the battery compartment in the winter?

  • Verde

    The title of this article is very misleading because Tesla removed “sleep” mode (due to other problems) in versions 4.2 and 4.3 of the cars firmware. I have a 60kWh car in California and I don’t loose anywhere near as much overnight so powering the onboard computers cannot be the dominant reason for the drain on David’s pack.

  • Suave001

    I have v4.5 and typically see a loss of about 2-3miles each night. Seems like a lot better than what was reported in the article but i’m sure that was on an older software revision.