Life With 2013 Tesla Model S: 'Vampire' Thirst For Electricity At Night?
![2013 Tesla Model S electric sport sedan [photo by owner David Noland]](http://images.thecarconnection.com/med/2013-tesla-model-s_100421970_m.jpg "2013 Tesla Model S electric sport sedan [photo by owner David Noland]")
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A couple of weeks ago, shortly after I took delivery of my 2013 Tesla Model S, I noticed that my home electric meter seemed to be running a bit faster than normal.
I keep a close eye on my meter, but that seemed odd.
After all, the long-awaited new luxury sport sedan delivered to my house in February by Tesla Motors [NSDQ:TSLA] was simply replacing electric miles I had been driving in my Chevrolet Volt.
The two cars have about the same efficiency in winter. So it shouldn't have taken notably more power to run the Model S than the Volt, right?
I decided to try an experiment. Unplugging my 60-kilowatt-hour Model S for the night at 9 p.m., I made a note of the Rated Range display, which read 169 miles.
Next morning, the range had dropped to 153 miles.
I left the car unplugged again the next night. (Temperature was in the 20s, a bit colder than the previous night.) Range dropped from 89 miles to 66, a loss of 23 miles.
What was going on here? Many days, I don't drive even 23 miles.
Was the Model S actually a "vampire" that used more electrical power just sitting overnight in my driveway than it might use during a typical day's driving for me?
Two more unplugged tests confirmed the pattern: 10 miles range lost in 9 hours, then 23 miles lost over 22 hours. On average, I'd been losing roughly a mile of range for every hour the car sat unplugged.
This was different: It wasn't just a design quirk, like the good and the bad points of the Model S that I wrote about recently.
This was taking money out of my pocket and putting carbon into the atmosphere.
No State-of-Charge Readout
Unfortunately, the Tesla Model S has no direct readout of the battery state of charge (SoC). There's just an undelineated bar graph that gives you a rough idea of remaining charge.
With no direct SoC readout (either as a percentage or in actual kWh), the only way to estimate vampire losses is to extrapolate from the lost range.
In normal driving, the Model S uses about one-third of a kilowatt-hour per mile. My apparent 24-mile-per-day loss thus translated into about 8 kWh of electricity. That's about a third of my total daily home electrical consumption, not counting the two electric cars.
If those mileage-loss numbers were correct, my Model S's apparent vampire losses would amount to almost 9,000 miles of driving a year.
Delusional Owner's Manual?
My numbers were wildly contradicted by the Model S owner's manual.
"When you're not driving Model S," it purrs reassuringly, "the Battery discharges very slowly to power the onboard electronics. On average the battery discharges at a rate of 1 percent per day."
One percent? Based on my unplugged mileage-loss numbers, my battery appeared to be discharging at about 12 percent per day.
![2013 Tesla Model S electric sport sedan [photo by owner David Noland]](http://images.thecarconnection.com/sml/2013-tesla-model-s_100421972_s.jpg "2013 Tesla Model S electric sport sedan [photo by owner David Noland]")
Hotline to the rescue
Tesla has recently established a hotline phone number for Model S owners with problems or questions, so I decided to give it a call.
The guy on the phone quickly confirmed the vampire problem. It seems that the "sleep mode" in the original Model S software--the basis for the owner's manual statements--had caused so many glitches in other car functions that it had been disabled.
With sleep mode missing from the current v4.2 software, he said, I could expect to lose about 8-10 miles of range per day when unplugged.
Using the rough three-to-one conversion ratio, that worked out to about 3 kWh per day.
He assured me Tesla was working to come up with new sleep-mode software as soon as possible, but he offered no estimate of how long it might take.
Last week, Elon Musk addressed the vampire/sleep-mode issue in a meeting with Norwegian Model S buyers in Oslo. Musk promised that the new sleep mode would reduce vampire losses to a mere 0.2 percent--a miniscule 170 watt-hours--per day.
And, he said, the new sleep-mode software would be installed by the time the Model S was introduced in Norway--currently set, he said, for July.
Faulty mileage readings
But my apparent vampire losses were more than double what the hotline rep said they should be. Did I have a special problem?
![2013 Tesla Model S electric sport sedan [photo by owner David Noland]](http://images.thecarconnection.com/tmb/2013-tesla-model-s_100421975_t.gif)
![2013 Tesla Model S electric sport sedan [photo by owner David Noland]](http://images.thecarconnection.com/tmb/2013-tesla-model-s_100421969_t.gif)
![2011 Chevrolet Volt and 2013 Tesla Model S [photo: David Noland]](http://images.thecarconnection.com/tmb/2011-chevrolet-volt-and-2013-tesla-model-s-photo-david-noland_100427529_t.gif)
![2013 Tesla Model S before DC-to-Boston road trip, Feb 2013 [photo: Aaron Schildkraut]](http://images.thecarconnection.com/tmb/2013-tesla-model-s-before-dc-to-boston-road-trip-feb-2013-photo-aaron-schildkraut_100419337_t.gif)
![2011 Chevrolet Volt and 2013 Tesla Model S [photo: David Noland]](http://images.thecarconnection.com/tmb/2011-chevrolet-volt-and-2013-tesla-model-s-photo-david-noland_100427533_t.gif)
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Have an opinion?
My understanding is that there are two optimal temperatures for a battery, one for running (warm) and one for storage (cold).
But a colder temeprature reduce "aging" process of the battery. That is why it is better to store the battery at a colder temperature for "long term" storage.
I wouldn't call 1-2 week a "long term" storage. But there is no way the car would know.
Maybe an option would be nice. However, that will leave the option to users who have NO idea how battery works...
This is not an "EV" issue at all. If you leave the dome lights and radio on in your gas powered car it will drain the battery. Or if you did the same thing on your Volt you would have reduced range in the morning.
Same issue, except the losses are from the computers.
Tesla's the computer is constantly in a sleep mode or standby so when it sense the key, the door handles has to pop up and the car has to be ready to drive.
Volt's computer doesn't come on until you press the power/on button on the dash. That is why it takes about 3-4 seconds for the Volt computer to do all the self check and before all the messages go away.
I don't see why Tesla can't switch to the Volt's on/off style. It is certainly easier on the standby/sleep circuits and will save a lot more power.
But Tesla wants to stand out and choose to be more "advanced" but it also takes on risk and potential problem.
Hopefully Tesla gets that sleep-mode sorted soon.
Don't get me wrong, I'm a huge Tesla fan. But Tesla needs for these issues to get some visibility so that they can continue improving the product.
However he is a self proclaimed early enthusiast and he writes articles about Tesla and the Model S so presumably he is well informed, yet he acts totally surprised by the sleep mode issue and lower range predictions after not plugging in during a cold night, even though countless readers of blogs like this could have told him about that, especially after "broder-gate".
Sorry, that all feels like an act to me. Don't know why he chooses to pretend fear uncertainty and doubt about his experiences with his car (vampire losses indeed...)but like I said: I know nothing about Mr. Noland.
As a plugin owners, those are important questions.
Criticism on real issues with the car is good. Borderline invention of problems isn't.
Those are EXACTLY the kind of "owner experiences" that I am looking for from Mr. Noland.
Really? You want to go there again. Time after time, I have critized GM's design in many area. I never ever said Volt is perfect or without fault. Yet, you have NEVER ever admit that Tesla can have fault.
Who is the "blind" follower here? Especially for someone who has NO EV ownership experience. As EV owners, we want to know all the positive and negative sides of the car. We don't blindly follow anything.
BTW, if you want to see a list of Volt issues, I will be gladly to provide you one.
Well, it is easy for some observer to call it "on the brink of solving it". The owners have to live with it today, tomorrow, the day after tomorrow until Tesla fix it. Of course, you don't own one so you don't have to worry about it. It is just all talks. Until you own it, then you would have to live with the problem. Until Tesla fix it, it is still problem for all existing owners as of today. Feel free to call it a "part of owners experience". If someone takes a trip of 3 weeks with their Tesla parked at airport, it would be nice to know.
Still can't believe he leaves it out in the open with a few rocks piled around it, maybe its the start of a garage!
The information about sleep mode being disabled is contained in the release notes, which is accessible through the touchscreen.
Great article and stunning vehicle, and kudos to your common sense sleuth-work- It's definitely on my next vehicle radar.
An interesting note, the Aptera IIe would drive about 50 miles on 4.5 kWh :-)
I agree that you should have a SOC gage readout option based in 100% being the 85, 60 or 40kWh battery pack. Tesla may not wan to do that because reading in their 2012 Form 10-K annual filing to SEC & investors, Tesla's battery and extended battery warranties do not include charge capacity as part of it. If loss of capacity turns up as an issue to customers, like it did with Nissan this past summer; Tesla can say too bad not cover in our warranty.
Thank you very much for all the updates on the Tesla S. Your experiences are exactly the kind of experience that I am looking for. Keep up the good work.
You mentioned:
"Heating or cooling starts automatically when you plug in, and charging begins when the Battery reaches the appropriate temperature"
I have read that some owners complain that the standard 120V (1.4KW) outlet can NOT keep the Tesla S at proper temperature in the extreme cold so its battery can't be warmed up with only a 120V outlet. Is this true? Have you seen such a problem with your Tesla?
As I iunderstand the owner's manual, when the battery needs to be topped off while plugged in, which can occur after 18 hours or more, there is a minimum threshold battery temperature required for charging. If it's colder than that, the battery will be warmed before charging starts. But most of the time, it just stays cold.
I haven't experienced this threshold temperature, so can't say whether a 120v outlet has enough juice to warm up the battery and allow charging to begin.
In the middle there the car might charge as fast as it can (which will heat up the pack on it's own) and use any spare power to heat the pack up faster.
I bet you could monitor this by looking at the dash when charging - the miles/hour charge rate should start low and then start climbing as the pack warms up while the volts/amps reading stays constant.
What if someone parks a Tesla S at a long term airport parking lot in the middle of winter and plugged into a 120V outlet, will it keep the car charged up at all?
With all the quirks that Tesla has, I still love to have one. But it doesn't mean it is perfect. This is exactly where people learn about a product's strength and weakness.
I read that you saw the "Olso video". In that same video Elon Musk tells the audience that "sleep mode" will return before EU deliveries and will consume 0.2% per day or 0.17kWh/day.
I noticed that in the last picture that you where charging the car outside is it normal kept outside or garaged. Would this make a difference ? I noticed in the reporters story that badged the S he parked it outside on a very cold night and the Tesla logs did show it lost a fair amount of range possibly this could be part of the problem.
EV = zero gas fuel
solar panels = zero utility bill
electric car + solar panels = complete independence in fossil fuels
also, i have doubts that the overnight losses you have observed will sustain itself over time. granted, this will be VERY difficult (for me anyway) but you should try letting it sit for 3-4 days. I am relatively sure your rate of phantom power usage will drop significantly.
another thing here is that most EV'ers have learned that your best course of action is
1) ignore the estimated range meter
2)get a meter that actually tracks the amount of charge in the battery. now with your range, this might not be a major issue, but in a LEAF
Two things are effecting your overnight energy drops. 1) the loss from systems remaining on (vs. sleep mode) & 2) lower temperatures with this time of year.
To get a better idea of the non-temperature related measurements you should park the S at a constant temperature garage. This should be fairly constant value vs. temperature related battery management use.
"Sleep mode" was disabled to avoid a software configuration issue as car wakes from sleep. Today's vehicles can have a 100 computer units in various subsystems. Most vehicles today are either on, or off… essentially the computers are rebooted each time vehicle is started. "Sleep Mode" is more common with PCs than cars and even with PCs it took time to realize expectations.
Placed overnight the range indicator did not loose a single kilometer, nor did the charge indicator lose a single percent
After an all night unplugged, plugging in did not activate the blower which always starts at the beginning of charge
Even if the vampire mode so eloquently described was active, it would cost me nothing because better-place pays the electric bill, regardless of where plug-in or batt-swap happens. I pay the miles-charge, and thats it.
Think about paying 30K dollars for a battery-pack that discharges incessantly every time you park. Ridiculous
So the car is fantastic but its achilles heel is as always the battery. At Tesla you pay for it and are stuck with it. Not at BP
It is totally unnecessary to have such a drain in an EV and it kills the joy.
As for the cold issue of the battery, that's one of the reasons I don't like batteries in the floor (exposed to cold). I want a tight block inside the car and thermally insulated such that a tiny amount of power can keep it at minimum temperature in cold weather. That way it could be ever ready even in -30c winters (unlike dumb ICE cars)
and you don't have these surprises of vanished range, nor delay before recharging.
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