Vampire Drain/Loss Tracking

[Daniel in SD]

Sigh...we are still on this?

If you don’t like features that require this, it’s best to just go with GM...they go hand in hand

I wish I could turn off the unique features that require the vampire drain. No one even knows what those features are though.
The Bolt isn't a perfect car either.

 

[AlanSubie4Life]

Sigh...we are still on this?

If you don’t like features that require this, it’s best to just go with GM...they go hand in hand

I don’t think there is any need to be dismissive. This is a completely legitimate concern which impacts usability of the car in some relatively uncommon scenarios (meaning it does not matter day-to-day, for the most part, other than the impact to efficiency), and likely is not helping long term health of the HV, the 12V, and the contactors.

I am not aware of any feature that requires this magnitude of drain, so far. When viewed from the HV battery side, 0W draw for 20 hours a day with 30W for 4 hours a day (to recharge the 12V 5W 20-hour drain) seems fairly reasonable (yes, it is still slightly high but would be totally manageable). Unfortunately we are not there yet.

 

[baton]

.5% = “big disappointment”?

You must have a generally wonderful life. I genuinely hope this is the worst challenge you are forced to face.

Please don’t take my feedback as an attack on Tesla. I really enjoy driving the car, and I fully support and love the change that Tesla has brought on the automotive industry, and with our feedback we are just trying to help Tesla improve and survive. Once the competition sets in, fully, any minor weaknesses will be exposed and there will be no mercy on the free market.

While 0.5% might seem insignificant its 50% more battery discharge than what Tesla is claiming on the manual. That’s a significant margin error, since days / miles add up. 30 miles loss in seven days for the car that hasn’t moved, sorry, but when comparing it to other electric cars there is a huge, I mean Huge difference.

If Tesla would have explained in details the reasoning behind this significant amount of power usage while the car is idle, perhaps we would all be at ease.

Thank you for your compliments

 

[Matt L]

Please don’t take my feedback as an attack on Tesla. I really enjoy driving the car, and I fully support and love the change that Tesla has brought on the automotive industry, and with our feedback we are just trying to help Tesla improve and survive. Once the competition sets in, fully, any minor weaknesses will be exposed and there will be no mercy on the free market.

While 0.5% might seem insignificant its 50% more battery discharge than what Tesla is claiming on the manual. That’s a significant margin error, since days / miles add up. 30 miles loss in seven days for the car that hasn’t moved, sorry, but when comparing it to other electric cars there is a huge, I mean Huge difference.

If Tesla would have explained in details the reasoning behind this significant amount of power usage while the car is idle, perhaps we would all be at ease.

Thank you for your compliments

Compared to other EVs? Exactly what other EVs are running features and downloading updates in the background? Seriously, where do you think this drain is going?

 

[Daniel in SD]

Compared to other EVs? Exactly what other EVs are running features and downloading updates in the background? Seriously, where do you think this drain is going?

My iPhone downloads updates in the background and only uses 1000x less standby power. Other EVs have apps too you know. ICE vehicles have over the air updates too.

 

[Matt L]

I don’t think there is any need to be dismissive. This is a completely legitimate concern which impacts usability of the car in some relatively uncommon scenarios (meaning it does not matter day-to-day, for the most part, other than the impact to efficiency), and likely is not helping long term health of the HV, the 12V, and the contactors.

I am not aware of any feature that requires this magnitude of drain, so far. When viewed from the HV battery side, 0W draw for 20 hours a day with 30W for 4 hours a day (to recharge the 12V 5W 20-hour drain) seems fairly reasonable (yes, it is still slightly high but would be totally manageable). Unfortunately we are not there yet.

I’m just tired of the two camps that completely dismiss each other. Half of this forum demands ever increasing features that stay on continuously to catch anything and everything around their car and then there are the vampire-drain hand wringers that suffer “big disappointments” when they have .5% more drain than they want.

Seriously, just stop and enjoy the car.

 

[AlanSubie4Life]

Exactly what other EVs are running features and downloading updates in the background? Seriously, where do you think this drain is going?

This is, indeed, the entire point of this thread; to track (and speculate) about where this drain is going. If you're not interested, or you already know the answer, this may not be the thread for you. It is quite mysterious to us. We have quantified some things:

Typical average draw is about 40W. That is a time-averaged value; it is probably never actually 40W; it jumps between a low value most of the time and a higher value for the rest of the time.

1) When in sleep mode, the draw from the 12V is 5W or less (based on battery tender data someone posted here), and the contactors are open so the HV draw is about 0. This would give 0.5miles/day on average. In this mode, you can access the car remotely! (Admittedly, it brings it out of sleep into idle, but it is listening.) You can also quickly enter the vehicle. So what this tells us: It is NOT the mobile access and it is not the door-handle-opening Bluetooth transceivers which account for the majority of the drain.

2) When in idle mode, the car draws at least 100W and as much as 400W or more. If the car were ONLY recharging the 12V battery (let's say it's in idle for 4 hours and sleep for 20 hours which is fairly typical), you would EXPECT about 30W to top off the 12V battery. (For an average draw from the HV battery of 5W which aligns with observation 1 above.) Let's say 40W during the 4-hour period to account for charging inefficiency. But the reality is that it is closer to 200W+ in this mode. So the question is why the extra ~150W+? Another consideration which impacts the duty cycle here, presumably, is how fast can an AGM be topped off without damage? Because if the load is so high in this mode, it makes sense to top that battery off ASAP and go back to sleep. But there may be limits on the 12V battery charger current (I don't know, and we don't have observational data on the charging behavior of the 12V yet).

3) As far as we can tell, this extra 150W is going to: Windshield heater (maybe at any temperature, but definitely when it is below 60 degrees), Ultrasonic sensors, camera, and what sounds like a pump. Presumably a large portion is going to the computer as well.

I am reasonably sure at this point that the data downloads/uploads are not the source of vampire drain. It's just not reasonable to think that, because an LTE (or WiFi) modem takes approximately zero power (in this context we can call it ~zero). It may be true that the computer has to be on to download such updates. But the car appears to turn the computer (and this other stuff) on even when it's not doing updates.

Half of this forum demands ever increasing features that stay on continuously to catch anything and everything around their car and then there are the vampire-drain hand wringers that suffer “big disappointments” when they have .5% more drain than they want.

I've checked - cabin overheat protection (when not actually cooling) & data sharing have no appreciable impact on vampire. Others have checked mobile access - also no impact. It'll be interesting to check sentry mode to see whether it has significant impact (if it is forced to stay in idle mode it seems like it will...will be interested to see whether the contactors stay closed in this mode when I get it).

Anyway, based on the observations, I think it's quite likely that both camps could get what they want. Though it is possible that there is no way to turn off the computer and other items when the contactors are turned on, which would mean we are possibly SOL, we're hoping that it IS possible and we can have the option to only recharge the 12V when we're in idle mode. Which would get us to less than 1 mi/day. Improvements beyond that would require optimization of the sleep mode draw.

 

[Daniel in SD]

I’m just tired of the two camps that completely dismiss each other. Half of this forum demands ever increasing features that stay on continuously to catch anything and everything around their car and then there are the vampire-drain hand wringers that suffer “big disappointments” when they have .5% more drain than they want.

Seriously, just stop and enjoy the car.

I have at least 10x more drain than I think is reasonable and as far as I know at least 10x more drain than any other brand of EV (or ICE!).
I would rather not waste energy. If people want to run sentry mode 24/7 that's up to them.

 

[Matt L]

This is, indeed, the entire point of this thread; to track (and speculate) about where this drain is going. If you're not interested, or you already know the answer, this may not be the thread for you. It is quite mysterious to us. We have quantified some things:

Typical average draw is about 40W. That is a time-averaged value; it is probably never actually 40W; it jumps between a low value most of the time and a higher value for the rest of the time.

1) When in sleep mode, the draw from the 12V is 5W or less (based on battery tender data someone posted here), and the contactors are open so the HV draw is about 0. This would give 0.5miles/day on average. In this mode, you can access the car remotely! (Admittedly, it brings it out of sleep into idle, but it is listening.) You can also quickly enter the vehicle. So what this tells us: It is NOT the mobile access and it is not the door-handle-opening Bluetooth transceivers which account for the majority of the drain.

2) When in idle mode, the car draws at least 100W and as much as 400W or more. If the car were ONLY recharging the 12V battery (let's say it's in idle for 4 hours and sleep for 20 hours which is fairly typical), you would EXPECT about 30W to top off the 12V battery. (For an average draw from the HV battery of 5W which aligns with observation 1 above.) Let's say 40W during the 4-hour period to account for charging inefficiency. But the reality is that it is closer to 200W+ in this mode. So the question is why the extra ~150W+? Another consideration which impacts the duty cycle here, presumably, is how fast can an AGM be topped off without damage? Because if the load is so high in this mode, it makes sense to top that battery off ASAP and go back to sleep. But there may be limits on the 12V battery charger current (I don't know, and we don't have observational data on the charging behavior of the 12V yet).

3) As far as we can tell, this extra 150W is going to: Windshield heater (maybe at any temperature, but definitely when it is below 60 degrees), Ultrasonic sensors, camera, and what sounds like a pump. Presumably a large portion is going to the computer as well.

I am reasonably sure at this point that the data downloads/uploads are not the source of vampire drain. It's just not reasonable to think that, because an LTE (or WiFi) modem takes approximately zero power (in this context we can call it ~zero). It may be true that the computer has to be on to download such updates. But the car appears to turn the computer (and this other stuff) on even when it's not doing updates.



I've checked - cabin overheat protection (when not actually cooling) & data sharing have no appreciable impact on vampire. Others have checked mobile access - also no impact. It'll be interesting to check sentry mode to see whether it has significant impact (if it is forced to stay in idle mode it seems like it will...will be interested to see whether the contactors stay closed in this mode when I get it).

Anyway, based on the observations, I think it's quite likely that both camps could get what they want. Though it is possible that there is no way to turn off the computer and other items when the contactors are turned on, which would mean we are possibly SOL, we're hoping that it IS possible and we can have the option to only recharge the 12V when we're in idle mode. Which would get us to less than 1 mi/day. Improvements beyond that would require optimization of the sleep mode draw.

Good reply.

I would assume the computer has to be on for downloads.

 

[Matt L]

I have at least 10x more drain than I think is reasonable and as far as I know at least 10x more drain than any other brand of EV (or ICE!).
I would rather not waste energy. If people want to run sentry mode 24/7 that's up to them.

I’m sorry but comparing what this car does or doesn’t do to other EVs or ICE just isn’t a valid comparison. If you want to say that based on data it’s too much, fine. But the comparisons aren’t valid. We’ve already determined that the things these cars are doing when not being driven, makes them unique.

 

[AlanSubie4Life]

I would assume the computer has to be on for downloads.

Sure. So that turning on of the computer should be needed about once a month. This is assuming I don't care about uploading all my data to Tesla (and I sure don't care, if they're going to turn on the computer to do so!) - and anyway, they could just perform that uploading function while the car is driving around, or when I happen to have the car door open in my garage in range of WiFi, when the drain is high anyway.

 

[Daniel in SD]

I’m sorry but comparing what this car does or doesn’t do to other EVs or ICE just isn’t a valid comparison. If you want to say that based on data it’s too much, fine. But the comparisons aren’t valid. We’ve already determined that the things these cars are doing when not being driven, makes them unique.

Tesla should give us an option of turning off the things the car is doing while not being driven. If people want those unique features that's fine, I personally would rather save the energy. I really don't think I would miss them since I don't even know what they are.
Look, I know the Tesla demographic (rich Americans) is one of the highest energy consumers in the world so it doesn't seem like a big deal to most owners. The vampire drain just seems so wasteful to me and I'm convinced with a little bit of engineering time they could save an enormous amount of energy (when you multiply it by the number of Model 3's).

 

[Magnets!]

Looking at the interior temperature when my car is parked overnight, I'm always struck by the fact that it seems warmer than I would expect (not charging). Granted I never had an interior temperature gauge in my ICE vehicles but I'm wondering if there is battery warming/conditioning going on overnight? I'm in So Cal, so no freezing temps and car is garaged. Certainly could be a significant part of vampire drain.

 

[AlanSubie4Life]

Looking at the interior temperature when my car is parked overnight, I'm always struck by the fact that it seems warmer than I would expect (not charging). Granted I never had an interior temperature gauge in my ICE vehicles but I'm wondering if there is battery warming/conditioning going on overnight? I'm in So Cal, so no freezing temps and car is garaged. Certainly could be a significant part of vampire drain.

I don’t think additional warming is taking place. It is possible that if you hit an idle cycle just right, some of that 200W of heat might still be hanging around. But vampire drain losses are really pretty small in the big scheme of energy required to significantly heat the cabin (you can easily lose a mile of range in a couple minutes with the full ~10kW of heating). So it won’t be much heating from vampire losses.

Anything is possible though I suppose. It just requires a lot more heat to do anything meaning for the battery than what we are seeing here. (Battery heating currently maxes out at 2.5kW apparently.). There really is no good reason to heat the battery, unless you are going to drive the car imminently or you currently are driving.

 

[Magnets!]

I don’t think additional warming is taking place. It is possible that if you hit an idle cycle just right, some of that 200W of heat might still be hanging around. But vampire drain losses are really pretty small in the big scheme of energy required to significantly heat the cabin (you can easily lose a mile of range in a couple minutes with the full ~10kW of heating). So it won’t be much heating from vampire losses.

Anything is possible though I suppose. It just requires a lot more heat to do anything meaning for the battery than what we are seeing here. (Battery heating currently maxes out at 2.5kW apparently.). There really is no good reason to heat the battery, unless you are going to drive the car imminently or you currently are driving.

I don't think there is cabin heating per se going on but rather heat soak from the battery. Whether that battery heat from driving lasts for hours and warms the cabin or if the pump is cycling warm water through it when parked I don't know.

 

[AlanSubie4Life]

I don't think there is cabin heating per se going on but rather heat soak from the battery. Whether that battery heat from driving lasts for hours and warms the cabin or if the pump is cycling warm water through it when parked I don't know.

That’s possible. The battery is 1000+ pounds, with decent heat capacity, which probably has a few kWh of energy pumped into it in the form of waste heat, for a full discharge, some of which it would retain for a bit. But, it also is not particularly well insulated, so I would think there wouldn’t be much left at all after 10 hours - might well still be noticeable after a couple hours though. It does take quite a while to “cold soak” a battery.

The pump seems to cycle coolant after a drive, for a while, which makes some sense. I don't know whether I've ever observed it running after the car has been sitting for days (which would not make much sense).

 

[baton]

I’m just tired of the two camps that completely dismiss each other. Half of this forum demands ever increasing features that stay on continuously to catch anything and everything around their car and then there are the vampire-drain hand wringers that suffer “big disappointments” when they have .5% more drain than they want.

Seriously, just stop and enjoy the car.

That’s right, you getting concerned with other people’s concerns will get you all tired up unnecessarily. Sorry but it’s not right you telling others what to think or not to think about their experiences with the car.

It’s okay and I respect that you don’t care about the daily 1% (4 miles) battery drainage while the car is parked.

This topic is exploring what some of Tesla customers suspect unnecessary wasted battery drainage and maybe there can be a software fix for it, hence helping Tesla improve the battery efficiency. When we add it all up, approximately, we are talking about a capacity loss of 4 miles a day x 365 days = 1,460 miles loss a year. That’s probably more than 1 month of driving for many. That's a lot of waste!.

How will Tesla improve if we as customers don’t provide a genuine feedback about our experiences with the car? Live up to your logo, enjoy driving your car and worry less about worries of others. No need to fight here when I believe we are all on the same side – rooting for Tesla’s success

 

[Matt L]

That’s right, you getting concerned with other people’s concerns will get you all tired up unnecessarily. Sorry but it’s not right you telling others what to think or not to think about their experiences with the car.

It’s okay and I respect that you don’t care about the daily 1% (4 miles) battery drainage while the car is parked.

This topic is exploring what some of Tesla customers suspect unnecessary wasted battery drainage and maybe there can be a software fix for it, hence helping Tesla improve the battery efficiency. When we add it all up, approximately, we are talking about a capacity loss of 4 miles a day x 365 days = 1,460 miles loss a year. That’s probably more than 1 month of driving for many. That's a lot of waste!.

How will Tesla improve if we as customers don’t provide a genuine feedback about our experiences with the car? Live up to your logo, enjoy driving your car and worry less about worries of others. No need to fight here when I believe we are all on the same side – rooting for Tesla’s success

The answer is obvious...they should stop giving you features that GM doesn’t have. That way they can compare with those awesome cars.

So basic.

 

[Daniel in SD]

The answer is obvious...they should stop giving you features that GM doesn’t have. That way they can compare with those awesome cars.

So basic.

Why not just give us the ability to turn off these unique features?
My car is in plenty awesome while driving it. I’m fine with it turning off when I’m not driving it. Not everyone cares how awesome there car is being when they aren’t in it.

 

[electrictorque]

Just like mentioned here, I think a lot of the vampire drain is being caused by the little windshield defroster/heater located right in front of the camera. When home I keep my car in a attached garage that is usually at around 70 degrees. Today I decided to clean the windshield and noticed that the area right in front of the camera was much warmer than the rest of the windshield. I reported this to Tesla.

Yes the car was in sleep mode..