Will the model 3 have vampire drain too?

Will the model 3 have vampire drain too?

The model S consumes approx 30 watts permanently while parked, 0,72 kWh/day and 263 kWh/year. Will this be the same for model 3? Is there a Chance to reduce? Other EV's like BMW i3 and Renault Zoe don't have the Problem, although range is meanwhile nearly similar. What with the Bolt?

Of course a solar roof will help a lot and therefore it is very useful. But only the sun is shining and not at Night. Wouldn't it be better to have the function to power off all systems completely? The Lion battery doesn't need heating or cooling when not in use. I would accept waiting 10 minutes running up and Start the car after parking 3 weeks at an Airport....

Since Model 3 will get the new type cells 2070 i am pretty hopeful....

Rocky_H | November 8, 2016

30 watts is almost nothing and is great. Also, you wouldn't be able to have remote access to the car if everything was turned off. If you want to turn it all the way off, you have the option on the touch screen and are totally welcome to do that.

Frank99 | November 8, 2016

30 watts in standby is absolutely unacceptable in an electronic system in 2016.

A standard car 12V battery is about 60 amp-hours, or about 720 watt-hours - that 30 watt drain will kill it in 24 hours (surely this isn't the case, or does the S charge the 12v battery when the car is off?).

It's completely understandable that there will be additional power drawn when the car is uploading daily logs to the mothership, downloading new software releases, or performing some local action like charging. However, when all those tasks are done, the electronics should be drawing milliamps, not amps.

The car needs to be listening for the remote to come in range - that's the equivalent of an old-time pager and a set of AA batteries lasted a month or more in those 20 years ago.
The car needs to be listening on the cell interface for your remote app to tell it to turn on the A/C - my phone on it's 3 Amp-hour battery can do that for a week before the battery dies.
The car needs to be looking for your hand to approach the handle in order to extend it - I design chips that perform this kind of function, and they draw microamps while waiting and checking.
Perhaps the car needs to check the temperature on a regular basis in order to cool the battery if necessary - that shouldn't need to happen more than, perhaps, once an hour and shouldn't take more than a few milliseconds.

What other functions is it performing that need power? Vampire power drain in the Tesla is a huge black mark against the quality of its electronic design. Proving that a complex electronic system can do its job without sucking vast amounts of power would be a great way to embarass all those purveyors of cable boxes and other electronics in our current lifestyle that save a few bucks during development and push that cost onto you in the form of measurable always-on power.

dave.m.mcdonough | November 8, 2016

It might be an average that includes running heaters to keep the pack above freezing or circulating the cooling pump.. I wish I knew. You're right that in a typical car this would be terribly unacceptable. It wouldn't even start after an 8hr shift.
Luckily that giant battery pack could deal with that for weeks. People even camp for days on it, using it to run heater or AC.

PhillyGal | November 8, 2016

@Frank - Unacceptable? I know about 100,000 Tesla owners that disagree.

The ability to control, heat and cool the car at any time is well worth the insignificant losses in range.

Rocky_H | November 8, 2016

@Frank99, Yes, it does occasionally use the main battery pack to refill the 12V battery as needed.

bernard.holbrook | November 8, 2016

Anyone not happy with their Tesla S: I would be happy to trade it one for one for my Volvo S60R. Any takers?

I didn't think so.

danielebernd | November 8, 2016

If its true, that there is an option on the touch screen to turn the car all the way off I will be really happy....only this simple function is all I wish.
I don't need remote access or software updates all the time.
I mean this could be an improvement to the model S. Why do these high tec cars still have such things as an non efficient 12 Volts LeadAcid battery? I am pretty sure there could be something more efficient...
A voltage transformer or converter from 400 to 12 volts direct from the main battery?

danielebernd | November 8, 2016

You can always make a great car even more great...

Frank99 | November 8, 2016

danielebernd -
That's really the point I want to make. Vampire power consumption is a wart on the nose of such a beautiful car...

cb500r | November 8, 2016

The 12V is to start the computer. After power on, the HV-battery is generating the 12V.
I guess that even a Tesla has to stay compatible to existing computer and automotive technologies, e.g. for economy of scales and proven technologies.
Many computers I know have 3,3V, 5V and 12V, most cars have only 12V.
Some 12V-batteries do not loose a huge amount of energy by their inner resistances, so very similar to HV-batteries.
Everything above 60V needs to be disconnected due to safety reasons. Above 60V it's high voltage (HV) in automotive, as it can harm people.
Nonetheless, some car manufactureres already create 12V-LiIon-batteries, by combining three cells to a 12V-block. Should be easy for Tesla as the battery manufacturer. In addition, it can still be separated to the HV-pack.
One of the other companies is Porsche and the battery is... expensive.

danielebernd | November 9, 2016

@ Rocky_H - "If you want to turn it all the way off, you have the option on the touch screen and are totally welcome to do that."

Is that confirmed? Can I really disconnect the computer and all systems completely with consumption zero or nearly zero?

Otherwise to install a simple on-off switch in the 12 volts battery supply cable would be sufficient...

As I said I don`t need remote access and software updates etc. when I park the car for 3 weeks at an airport...

Rocky_H | November 9, 2016

@danielebernd, Quote: "Is that confirmed? Can I really disconnect the computer and all systems completely with consumption zero or nearly zero? "

Yeah, my Model S has had that function on the touch screen ever since I got it in early 2014. I think all of them have always had that.

jordanrichard | November 9, 2016

Ummm one small problem with a complete electronic shut down, how will the car know to unlock when you approach the car. Also if you put your car into complete shutdown with no connectivity, how are you going to know if your car is begin stolen (flat bedded).

Frank99 | November 9, 2016

Agreed; which is why I'm not proposing a complete shutdown. I'm simply proposing a smarter system design that takes 30 milliwatts in standby doing everything that it does today, rather than taking 30 watts as the current Model S implementation seems to take. .

Kyuu | November 10, 2016

Where are you getting the 30 watt figure from in the first place? Just curious.

Nexxus | November 10, 2016

I left our MS60D unplugged for the last two nights and the car exhibited no drain whatsoever. I started out with the same miles left on the battery as the night before. We are just loving this car more and more!

topher | November 10, 2016

@Frank: "I'm simply proposing a smarter system design that takes 30 milliwatts in standby doing everything that it does today, rather than taking 30 watts as the current Model S implementation seems to take."

Well if you are an electrical engineer, and have enough knowledge to think that the current system have that much waste in them, *please* send a resume to Tesla. It isn't like they prefer to use 1000 times too much power.

Proposing a 1000 times increase in efficiency without any way to accomplish it, is not very helpful.

Thank you kindly.

Frank99 | November 10, 2016

Kyuu -
The 30 watt figure comes from the OP. I don't know whether it's valid or not. Not currently owning a Tesla I don't have access to an owner's manual, but various posts indicate that the owner's manual claims a 1% per day loss from the battery. 1% of 60 KWhr in 24 hours is about 25 watts.

Topher -
I am in fact an engineer, and would love to work for Tesla if I lived anywhere near them. Alas, I instead live in a place where I can actually afford to purchase a house.

But that's irrelevant. My original post contains sufficient real-world examples of systems that perform the functions of a parked Tesla to prove that it's possible to do. A modern cellphone is perhaps the simplest; all the functions of an idle parked Tesla are actually performed by my Samsung Galaxy S6 in ultra power savings mode, and it'll last for at least 5 days - which works out to about 0.075 watts of average power, which isn't the 1000 times improvement you scoff at, but is close at a mere 400 times times improvement.

Part of the path to achieving a solar electric economy must be efficiency - the less electricity you need to use to perform a function, the less electricity you need to generate and store and the less that gets lost in inefficiencies - transmission losses, charging/discharging inefficiencies, etc. Burning 30 watts just sitting, parked, is a slap in the face to efficiency, in addition to being something that some owners have to consider that they shouldn't have to.

Kyuu | November 10, 2016

If the manual claims a 1% loss per day, that must be a really rough estimation that's difficult to draw any good data from, as that would mean different rates of depletion depending on the size of the battery (1% of 100kWh is a loss of 1kWh per day, whereas 1% of 60kWh is only 0.6kWh per day). I doubt there's any reason why the bigger battery packs would exhibit more "vampire drain". I'd bet the wording is actually more like "less than 1% per day".

I'm sure there is some drain from all the sensors, antennas, and computer systems in the vehicle. But, without some actual data on this supposed drain, I don't think it's worth getting worked up over.

cb500r | November 10, 2016

I also wouldn't trust the 1%.
Might be similar to oil consumption of 1l/1000km in some manuals...
I never had a car with that consumption.
LiIon-batteries have a very low tendency for self emptying and a smartphone (how much additional power is needed for activation, doors,...) has how many amps?
World is green.

Tiebreaker | November 11, 2016

A good write-up by our fellow poster Teslarati

Also check Bjørn Nyland's video of YouTube, referenced in the text,

topher | November 11, 2016


"I am in fact an engineer"

Excellent, I look forward to hearing your practical engineering recommendations for reducing the power consumption of idle Teslas by 400 times. Or just send them to Tesla, and I will enjoy them when they are put into production.

Thank you kindly.

Frank99 | November 11, 2016

topher -
So because you don't understand the system, you get dismissive? Perhaps you should hold your tongue in discussions where you're unable to contribute anything more than a belief that the conversation shouldn't be occurring.

Kyuu | November 11, 2016

Thanks for that link Tiebreaker, that provides a little bit of real world data.

So between that post and Bjorn Nyland's report, it seems the amount of drain can vary quite a bit. Both were in low temperature environments, with the one from Teslarati being colder and having a correspondingly higher amount of drain. Perhaps most of the drain they were seeing is from the heater keeping the battery from freezing and/or cold-induced battery loss? Are there any reports from Teslas parked long-term in more temperate environs?

topher | November 11, 2016


Sorry for painting you into a corner. Since you claimed to be an engineer, and claimed to know that the system can run on 30 milliwatts instead of 30 watts, I assumed that you must know how that can be accomplished. No engineer would just make the claim without knowing something about what he was talking about. You now know that making claims like that will be called, be prepared to put your cards on the table.

Thank you kindly.

Frank99 | November 11, 2016

Topher -
Too big of an order.
I am ignorant of the actual hardware and software that Tesla has chosen, so I can't suggest how Tesla could modify what they have. They could have one main CPU that runs everything, or they could have 100 different CPUs each running one thing. I assume that their engineers are smart guys, and they've gone through several attempts to reduce standby power, That means that ability of the system for low power operation is limited to where they are now, and that's where it'll stay until there's a major redesign. Perhaps with the AP2 hardware update they've taken the opportunity to do that major redesign with the inclusion of the NVidia GPU for processing AP2 data.

Given a clean sheet of paper, I'd start the design with a networked cluster of systems - system controller, Display and infotainment, motor control, AP compute, AP data collection, ABS, etc. The system controller is the only system that's powered up and running while the car is parked. This controller needs to be exceptionally low powered, needs to be able to communicate with a baseband processor for LTE connectivity, needs to have an RF transceiver available for communications with the key fob, and may need WiFi connectivity that can be powered down when unneeded. Today, a great match would probably be something like a Qualcomm Snapdragon 810 with, perhaps, two GB of LPDDR and 16 GB of Flash and onboard LTE baseband, with something like an NCF2960 for keyfob communications. Power could be provided by a switching supply from the 12V battery. The software environment would be a Linux derivative designed for low-power systems similar to what runs underneath Android. At full speed with 4 cores running, power is on the order of a couple of watts; while idle, maybe a milliamp or two. This system controller hardware costs on the order of $20.

This system controller would be able to wake and communicate with all the other independent systems in the car. For ease of maintenance and development, wherever possible the other systems should run on similar hardware and software environments, although safety critical systems (ABS, Motor Control, etc) and other specialized systems will likely run on bespoke hardware/software.

Because rapid response/boot is probably necessary for these systems, any of the Linux-based systems other than the system controller should implement a rapid boot system, probably in a dual-level system - LPDDR left powered for up to, say, 24 hours to provide millisecond-level wake-and-respond times and 10's of milliwatts standby, with a fast FLASH for hibernation longer than that to provide zero milliwatt standby and 4-5 second wake and response time - still faster than a normal person could walk up to the car, get in, and expect a response from the screen; they'd never know the difference in the two modes.

The system controller spends essentially all of it's time in a clock-stopped, lowered voltage state waiting for an interrupt from either the keyfob transceiver or from LTE. Upon receiving the information from whatever wakeup device is activated, the system controller wakes the necessary systems. If, for example, the mothership needs to download a new software update, the largest storage system in the car (perhaps the Display system) is woken, the WiFi is activated on the system controller and a session established with Tesla, and the update is downloaded to the storage ready for you to agree to the install in the morning. The display system, with nothing more to do, goes back to sleep.

This is embedded system design 301. My guess is that standby power really wasn't a requirement, and the engineers didn't pay close attention to low power design because they knew they'd be hooked up to half a ton of batteries. They probably didn't notice until they'd integrated all the systems, measured power, and someone calculated battery usage over a month late in the development and someone said "Oh, crap". But by then it was too late to change things.

The systems I design currently are smaller; the last ASIC I designed consumed on the order 15 microwatts while constantly looking for a person to come near, then booting within 3 milliseconds to perform it's function while taking 300 milliwatts or so, and simultaneously waking a larger system with a display to provide information to the user within 100 milliseconds or so.

Please take my word for it that low-power embedded systems design (even complex, distributed systems with many nodes as one might find in a high-tech car) is a well-understood and well-supported endeavor these days. Having 100 computers in a car, some with the CPU power of a flagship cellphone, some with the CPU power of a high-end desktop GPU, some with the CPU power of a $10 digital watch, doesn't need to imply tens of watts of power when the system is idle.

I hope that's good enough for you, because I choose to stand down now.

bernard.holbrook | November 12, 2016

@Frank99- Good food for thought but the T3 is pencils down. If we want to see a T3 in late 2017, Tesla needs to focus on getting the car as designed into production.

If is was a safety issue, by all means, redesign and be a bit late but a drain of 30 watts (or less) is nothing to me.
Cost is 30w times 24 hours times about $.12 (power/kwh); so about 9 cents a day.

@danielebernd - I would not accept any start delay to save 9 cents a day. I do get the need to have a long term storage shutdown option but other posters say it all ready exists by shutting the car down with the display.

Haggy | November 12, 2016

If you want to know about the real world concerns, you can read some of the threads in the Model S forum, but it doesn't come up very often because there's not much of a practical concern.

If you lose 2-3 miles or range per day, you'd probably still be fine leaving it at an airport parking lot for a month. If you charge at home each day, it might mean a difference of a few minutes a day in terms of when charging finishes, but you'll be asleep and will never see it. On long trips, you won't have enough time between chargers for vampire loss. If you leave the car parked overnight when you go camping in the woods for three days, then when you get to the next supercharger, it might take an extra minute and a few seconds to make up for the vampire loss. I charge when I stop for meals or restroom breaks so I won't ever see a difference.

It could conceivably cost an extra $150 over the course of ownership for a typical owner. Is it worth it? It might cost me $6000 for cable TV over that same period. It all comes down to what you like. I'm sure I saved enough money to pay for a Model 3 by not having cable TV at all, compared to what it might have cost for a premium package. So for me, if it comes out to a dollar a month for vampire loss, and I factor in what I'm saving in gas, I end up with nonsense since I wouldn't buy a car that runs on gas so it's not even a fair comparison. You can't buy something else and save money compared to having vampire loss. You could buy a cheaper car and save money since the car is cheaper.

cb500r | November 12, 2016

Nice, well done and hopefully engineers at Tesla are smart enough to create the system with a main system controller and everything else shut down.
This is what I would expect from a modern, high efficient, environment friendly, fresh designed car.

danielebernd | November 13, 2016

It still remains a disadvantage
The model 3 will be built 400000 times or even more.. why not try to achieve the best ?
You can always make a great car even more great.

danielebernd | November 13, 2016

I just found on youtube:


danielebernd | November 13, 2016

search for this in youtube:

Tesla Model S: Unplugged 11 days, Idle Range Loss Firmware 8 First Release

danielebernd | November 13, 2016

What I don't understand is that other electric car manufacturers don't seem to have the problem

kaffine | November 13, 2016

It really depends on what is causing the power consumption. If it is for battery temp regulation or battery conditioning then I don't have a problem with it. This I would think is the primary power use in standby. Now if it is just because they leave all of the electronics powered up all the time then they need to work on fixing that.

While I don't expect Tesla to have the same low level of standby power use as a space probe or a smart watch I also don't expect them to waste large amounts of power for no real reason. There are a lot of simple things to do to save power in standby that doesn't increase cost significantly I would expect Tesla to have implemented most of these. At some point however it starts costing a lot of money to make very small gains while this is worth it for smart watches and space probes it isn't worth it for a car with a 40+kWh battery pack.

Now using power to maintain battery temp within a certain range that they have found works best for battery longevity I would consider acceptable. Using 30 watts constantly is going to extend the battery life another year or more then that is what it takes. Using 30 watts all year is 263kWh or about $40 of electricity per year well worth it if that extends the battery life. Temp regulation tends to use power even the most efficient systems consume a decent amount of power. It's not like they can use a ground source heat pump they have to use air source or resistive heat.