Vampire Drain/Loss Tracking

[eprosenx]

DREAM CAR: 300mile battery with manual seats, mirrors, etc. for 30K that lasts 500k miles. No cameras, no sensors, no apps, no bluetooth. Nothing wrong with computer and software to maintain the DRIVETRAIN only. Get an update when you are in range of wifi. I believe it can be built pretty easily by Tesla and profitable.

A car is a tool.

Man Teslas could've been so great. Now what, Volkswagen? Rivian? Doubt it, they're all planning wasteful "features" too. Oh well.

I agree there is a market for a more “basic” car.

The reality is that right now they can earn a lot more margin on these really high end cars, so that is where everyone is entering the market.

Once that demand is satiated they will make some more stripped down versions. The issue is that the underlying base core drivetrain is really expensive and so there is a limited market for a stripped down $30-35k car.

I actually am really excited for a really stripped down truck. Something you can hose out, no features, but has one electric motor per wheel for great traction.

 

[gary3411]

The issue is that the underlying base core drivetrain is really expensive

Are you sure about that? Of course it's expensive, but I believe there is close to $5,000 worth of unnecessary baggage on the model 3. If you include the R+D and software to run all that stuff, probably more than $5,000.

I actually am really excited for a really stripped down truck. Something you can hose out, no features, but has one electric motor per wheel for great traction.

Do you really think that will come? If so, that'd be great!

 

[gary3411]

I think the demand is satiated. They're answer seems to be autonomy. I'd rather see capital used to build a better 'value' (not cheap!) car to lure more economy/utlity car owners away from gasoline. Then they can work on autonomy in high end models.

 

[gary3411]

Point being, they can still have plenty good margins. Even if they are slightly smaller. 15% margins on 500k vehicles is better than 20% on 300k. Yes it would take a separate dedicated line.

 

[AlanSubie4Life]

Point being, they can still have plenty good margins. Even if they are slightly smaller. 15% margins on 500k vehicles is better than 20% on 300k. Yes it would take a separate dedicated line.

The impression I get is that right now they have a hard time making enough batteries to support their cars and their other endeavors concurrently. Also, right now, not everyone could drive an electric vehicle even if they wanted to - the manufacturing capacity just isn't there. At least the transition has started. But that's a topic for a different thread.

For the vampire drain issue, I would not count on it being fixed, but I do think it could be made better by Tesla. I'm not holding my breath. Part of the issue is that no one outside of Tesla really knows exactly why it exists, or what purpose it serves.

I knew about the vampire drain before I bought the car, it's just as annoying as I expected it to be, but I have no regrets about the car. I like to drive cars quickly and go around corners quickly, and the Tesla is a great car for that. I was getting super annoyed by the noise of ICE vehicles, breathing in my stinky Subaru exhaust, and the filth and maintenance that I had to deal with doing my own service on those vehicles. The Tesla has eliminated those annoyances. I don't have any illusions about it staying trouble-free - I'm sure something odd and silly will break soon enough - but, I won't have much choice but to let Tesla deal with it most likely. So, problem solved, sort of.

Best of luck with your decision. If you're going to be routinely in remote areas with little access to charging, you do need a plan with any electric vehicle, and especially an SR. Charging infrastructure is still pretty limited, though improving.

Maybe this summer I'll try to take mine to the North Rim of the Grand Canyon. Should be interesting if I do.

 

[eprosenx]

The impression I get is that right now they have a hard time making enough batteries to support their cars and their other endeavors concurrently. Also, right now, not everyone could drive an electric vehicle even if they wanted to - the manufacturing capacity just isn't there. At least the transition has started. But that's a topic for a different thread.

For the vampire drain issue, I would not count on it being fixed, but I do think it could be made better by Tesla. I'm not holding my breath. Part of the issue is that no one outside of Tesla really knows exactly why it exists, or what purpose it serves.

I knew about the vampire drain before I bought the car, it's just as annoying as I expected it to be, but I have no regrets about the car. I like to drive cars quickly and go around corners quickly, and the Tesla is a great car for that. I was getting super annoyed by the noise of ICE vehicles, breathing in my stinky Subaru exhaust, and the filth and maintenance that I had to deal with doing my own service on those vehicles. The Tesla has eliminated those annoyances. I don't have any illusions about it staying trouble-free - I'm sure something odd and silly will break soon enough - but, I won't have much choice but to let Tesla deal with it most likely. So, problem solved, sort of.

Best of luck with your decision. If you're going to be routinely in remote areas with little access to charging, you do need a plan with any electric vehicle, and especially an SR. Charging infrastructure is still pretty limited, though improving.

Maybe this summer I'll try to take mine to the North Rim of the Grand Canyon. Should be interesting if I do.

Yeah, I share the frustration about having to worry about your car being dead when you come back from a trip away with no charging ability (i.e. like the airport). While in daily use this is *never* an issue for me (with my LR), it could / would be when I go out to the woods, etc...

I am actually seriously concerned that Tesla has come up with an architecture where this is a fundamental core limitation that will never be solvable with software updates.

If I were designing the systems for a Tesla, I would probably take a cell phone chipset and make that my main "always on" computer with LTE connectivity. Then other vehicle subsystems could stay powered off at all times. With the battery size in a Tesla you should be able to run a cell phone for like an entire year without recharging...

It feels like the way Tesla has implemented things, they have to keep a fairly "hungry" computer running at all times to enable things like keyless entry, remote vehicle queries from the Tesla app, the charging port wireless receiver (which by the way utterly fails a lot if the car is asleep), etc...

Anyone here have a block diagram of the various computers in a Model 3 and what their functions are?

 

[seattlite2004]

From the latest Rich Rebuilds video, the Integrated Car Computer which houses the MCU as well as the Autopilot boards is liquid cooled from the same coolant loop as the rest of the car. So wonder if the Car Computer is running but car is "off" whether the coolant loop pumps are running. Those pumps must be drawing a bunch of power.

 

[OCR1]

I average 12 miles/day of vampire loss. The loss is attributable to the car being parked as well as the battery drain from using dash cam and sentry mode. My experience with dash cam is that it continues to run even after I park my car until the car goes to sleep, so that adds further stress on the battery. Eventually I'll try removing the memory card to see how much the drain is reduced.

 

[AlanSubie4Life]

From the latest Rich Rebuilds video, the Integrated Car Computer which houses the MCU as well as the Autopilot boards is liquid cooled from the same coolant loop as the rest of the car. So wonder if the Car Computer is running but car is "off" whether the coolant loop pumps are running. Those pumps must be drawing a bunch of power.

Anyone have the number of watts required to run a very small pump? I don’t have a good sense but I would guess less than 10W?

I tend to think it is the computer itself (see @eprosenx comments) that would dominate the power draw - if the cooling loop is running to cool it, it seems probable the computer would be the dominant contributor!

 

[coleAK]

Options on a vehicle are almost all profit. That is why the “average” 1/2 ton truck is over $50k. And why Porsche was the highest profit margin car company for years. I’m active on the land cruiser forums and on there there is constant discussion around the wish for a “basic” version (basic radio, cloth seats, rubber floor, ...) of the 200 series like other parts of the world. I read an interview with a guy from TRD and he basically said: they don’t sell many “basic” versions of Tundra, 4 runner, or Sequoia. so why would the offer a $50k version of the LC when they sell the $85k+ ones just fine.

Look at how much people complain about not having the newest tech. My sister in law traded her 4 year old ~30k mile suburban LTZ on a new suburban LTZ and took a $35k beating to get 99% the same truck just to get Apple play (whatever that is). I’m saying there is no way a basic version of the LR 3 would sell enough to cover the cost of differences in manufacturing.

As far as drain. Our 3 just sat in the garage at 55F for 11 days. Unplugged, no apps, didn’t wake it up once from the app. Weren’t from 70% to 65% It lost 5%. Seems pretty insignificant.

 

[AlanSubie4Life]

I am actually seriously concerned that Tesla has come up with an architecture where this is a fundamental core limitation that will never be solvable with software updates.

I am worried too. It seems that they have to power up the computer and go to idle (seems to be about 200W) in order to turn on the DC/DC converter which recharges the 12V, to replenish it, due to the approximately 7W constant load on it in sleep mode.

If there is no way to significantly reduce that 200W draw - if it’s just the “on” power, then we are out of luck. They would just have to minimize the time in that mode by charging that 12V as quickly as possible with the DC/DC. That’s the best they could do. Might mean that you must spend at least an hour each day drawing 200W which would mean a minimum of 1 mile of drain.

All the connectivity stuff just draws a few watts (which is awful but a whole order of magnitude lower), so the vampire is not primarily due to those functions. (As evidenced by all the most useful features of the car operating while it is asleep, not idle - for example you can walk up to it and open it - charge port release as you mention is the only exception I know of) The majority of the vampire is more of a side effect of recharging the 12V which must be done due to the drain caused by the sleep mode features, as far as I can tell.

 

[seattlite2004]

Anyone have the number of watts required to run a very small pump? I don’t have a good sense but I would guess less than 10W?

I tend to think it is the computer itself (see @eprosenx comments) that would dominate the power draw - if the cooling loop is running to cool it, it seems probable the computer would be the dominant contributor!

The coolant loop is pretty elaborate...I dont think its just a 10W draw:


https://jalopnik.com/the-tesla-model-3s-superbottle-easter-egg-is-a-fascin-1830992728
https://www.motortrend.com/news/tesla-model-3-teardown-details/

 

[AlanSubie4Life]

The coolant loop is pretty elaborate...I dont think its just a 10W draw:


https://jalopnik.com/the-tesla-model-3s-superbottle-easter-egg-is-a-fascin-1830992728
https://www.motortrend.com/news/tesla-model-3-teardown-details/

View attachment 406180

I realize that, but it could easily be less than 10W if just the pump is running (in fact I would hope so!). Just wondering, order of magnitude...

A good design would have the cooling apparatus be capable of extracting a lot more energy than the cooling apparatus itself generates. I would think.

 

[BestHand]

I am worried too. It seems that they have to power up the computer and go to idle (seems to be about 200W) in order to turn on the DC/DC converter which recharges the 12V, to replenish it, due to the approximately 7W constant load on it in sleep mode.

If there is no way to significantly reduce that 200W draw - if it’s just the “on” power, then we are out of luck. They would just have to minimize the time in that mode by charging that 12V as quickly as possible with the DC/DC. That’s the best they could do. Might mean that you must spend at least an hour each day drawing 200W which would mean a minimum of 1 mile of drain.

All the connectivity stuff just draws a few watts (which is awful but a whole order of magnitude lower), so the vampire is not primarily due to those functions. (As evidenced by all the most useful features of the car operating while it is asleep, not idle - for example you can walk up to it and open it - charge port release as you mention is the only exception I know of) The majority of the vampire is more of a side effect of recharging the 12V which must be done due to the drain caused by the sleep mode features, as far as I can tell.

I think that to monitor and recharge 12V battery no need to wake up computer, this simple function does not need a comp, can be done very simple. if Tesla wakes up computer just to monitor and recharge 12v it would be wasting a lot of energy, but Tesla somewhere said it also does some testing.
I think Tesla pump can draw much more then 10w and does it dynamically, changes the pump speed depends of necessity. When car is parked and no need to cool/heat the battery pump should work only enough to cool the computer, minimum, but I don't think it draw less then 10W.

 

[BestHand]

Anyone have the number of watts required to run a very small pump? I don’t have a good sense but I would guess less than 10W?

I tend to think it is the computer itself (see @eprosenx comments) that would dominate the power draw - if the cooling loop is running to cool it, it seems probable the computer would be the dominant contributor!

Looks like Tesla uses one computer for everything, from monitoring connections and low voltage battery to FSD, and power needed to do these jobs is quite different. I can imagine that for autopilot and FSD computer should have great computing power, but many times lower for other things. If Tesla had separate computers for this tasks, I believe vampire drain could be drastically minimized. It is possible that Tesla throttles computer if needed though.

 

[AlanSubie4Life]

Someone really needs to put a couple current clamps in the right places (DC/DC output, and also the feed from the 12V battery to the bus) and give us all the answers! So much to be learned...

 

[darth_vad3r]

Not sure when the last time someone quoted the manual on this was (if it was done already in this thread), so I thought I'd paste in what the current* version states:

"Battery Care
Never allow the Battery to fully discharge. Even when Model 3 is not being driven, its Battery discharges very slowly to power the onboard electronics. The Battery may discharge at a rate of approximately 1% per day. Situations can arise in which you must leave Model 3 unplugged for an extended period of time (for example, at an airport when traveling). In these situations, keep the 1% in mind to ensure that you leave the Battery with a sufficient charge level. For example, over a two week period (14 days), the Battery may discharge by approximately 14%."

*Source: currently on page 122 (PDF page 124) of the 184-page "PUBLISHED DECEMBER 20, 2018" version of the manual, here:
https://www.tesla.com/content/dam/tesla/Ownership/Own/Model 3 Owners Manual.pdf#page=124

 

[darth_vad3r]

Others have mentioned already that cells can lose charge on their own, aka "self-discharge", but I found some interesting numbers here I thought I'd add a comment about: Elevating Self-discharge - Battery University

Li-Ion there is noted as losing 5% in first 24 hours, then 1-2% (4-5%) per month with/without a protection circuit:

"Li-ion self-discharges about 5 percent in the first 24 hours and then loses 1–2 percent per month; the protection circuit adds another 3 percent per month."​

Obviously Tesla's cell chemistry won't exactly match whatever batteries have gone into feeding that data, and is probably improved over that, but my takeaways from that one line are that:

1. we shouldn't extrapolate loss for a week or month of storage based on measurements taken in the first 24 hours after a charge, since that seems to be much higher (75x higher with 5% in 1 day vs 2% in 30 days!).
2. 1% per day isn't really much, considering part (most?) of that is just self-discharge anyways. A rechargeable Li-Ion battery left in your drawer unused will likely lose more % in a week doing absolutely nothing at all than your Tesla will (and your Tesla is still actually doing stuff, like maintaining your 12V battery, connecting to internet, monitoring bluetooth, etc)

Personally, I've read that turning off Cabin Overheat Protection can save battery power because of not having to continuously monitor the temperature (even when it won't actually run because it's not hot enough) so I have turned that off. I was monitoring overnight drain more closely when I first got the car, but I've since stopped worrying about it so much, and tend to leave it plugged in at home overnight with the set point being just a smidge over whatever the current battery state is so it charges a very short amount of time and then maintains that level overnight (I do most of my charging at work).

 

[WilliamG]

As far as drain. Our 3 just sat in the garage at 55F for 11 days. Unplugged, no apps, didn’t wake it up once from the app. Weren’t from 70% to 65% It lost 5%. Seems pretty insignificant.

I’m losing roughly 2% per day on my P3D+ which is sitting outside the Tesla SC right now waiting for repairs.

 

[coleAK]

I’m losing roughly 2% per day on my P3D+ which is sitting outside the Tesla SC right now waiting for repairs.

How do you know? Are you checking it from your phone? Do you have any apps running? Cabin protection on?