Newbie doing some number crunching On Vampire drain.

[Niroc]

My last charge was completed with 217 miles of range. I now sit at day 5 with 133 miles left. Tesla last charge states 72.7 (73) miles, 14 kWh, and a 191 Wh/miles. So, it appears that I have lost 11 miles due to vampire drain in the past 5 days which is a little over 2 miles a day. (217 - 133) - 73 = 11.

Does this sound about average to you?

 

[hoang51]

Have you read the Model 3 manual to see what it states that is acceptable?

 

[AlanSubie4Life]

My last charge was completed with 217 miles of range. I now sit at day 5 with 133 miles left. Tesla last charge states 72.7 (73) miles, 14 kWh, and a 191 Wh/miles. So, it appears that I have lost 11 miles due to vampire drain in the past 5 days which is a little over 2 miles a day. (217 - 133) - 73 = 11.

Does this sound about average to you?

Not quite right.
Assuming an SR+....the 220Wh/rmi is an estimate; needs owner verification (anyone?). (rmi = rated miles, not to be confused with actual miles)
You used (while driving) 72.7mi*191Wh/mi = 13.89kWh which is 13.89kWh/(220Wh/rmi) = 63rmi

So, you've used in total 63rmi (on the meter) while driving (best estimate). No way to know - you would have to have been paying very close attention - but I'm guessing for you based on the 220Wh/rmi constant, that that is what it was.

So that leaves (217rmi-63rmi-133rmi) = 21rmi unaccounted for.

That's about what I would expect for 5 days (21 rated miles over 5 day - about 4 rated miles per day). The manual says you should expect 1% per day...not clear if that is actually applicable to the SR+; it might be a little more...or the same 3-4 miles a day Tesla says to expect for the LR.

11rmi over 5 days would be a lot lower than I would typically expect, and you can see from the numbers above it's very unlikely.

About 25% of your overall use is vampire drain, which is about right for a very efficient SR with 5k miles per year (70 miles every 5 days). For typical users with less spectacular efficiency and 10k miles per year, it would be more like 10%.

 

[srs5694]

Broadly speaking, there are at least two levels of vampire drain:

• Sleep mode -- When you park your Tesla for long enough, it eventually goes into a low-power "sleep mode." When in this mode, my Model 3 LR loses about 1 mile of range per day.
• Idle mode -- A Tesla enters idle mode for a while when it's parked but before it goes to sleep. Idle mode is also used when you activate Sentry Mode, when the car is downloading or installing a software update, when you check the car's status via the Tesla app on your phone, and so on. There may be some differences in range loss depending on exactly what the car is doing in idle mode, but the range loss is on the order of 1 mile of range per hour.

There may also be range loss for other reasons, such as if it's very hot or very cold out and the car uses its AC or heat to keep the battery at a desirable temperature, or if you precondition the cabin temperature (including using the cabin overheat protection feature). I took delivery of my Model 3 in late March here in Rhode Island, so I have yet to experience extreme temperatures and don't yet have firsthand experience with those effects.

Because the car spends some time idling before going to sleep, if you take a modest number of trips per day, you're likely to see a combined range loss of 3-6 miles per day if you don't use Sentry Mode or other features that keep the car awake, and 20 miles or more if you do use such features (at least, constantly). If you park for an extended period (like at an airport parking lot when you travel by air), don't use Sentry Mode, and refrain from checking the car's status via the app, your range loss is likely to shift down to closer to 1 mile per day.

FWIW, Teslas have more systems active when parked, so they do suffer more vampire drain than do most other EVs. This is a point that doesn't get much attention. Yes, Sentry Mode is cool; but if you make heavy use of it, it has an energy cost equivalent to driving hundreds or even thousands of miles per year.

 

[AlanSubie4Life]

Because the car spends some time idling before going to sleep,

Idle mode -- A Tesla enters idle mode for a while when it's parked but before it goes to sleep.

Idle mode is also the only way the car has to recharge the 12V battery from the sleep period drain (drain in sleep mode is just a few watts, less than 6-7W I think - works out to a bit less than 1 rated mile per day for sleep drain). So it is required to transition to idle mode periodically, there is no avoiding it, even if you never check the car status. The HV contactors have to close (you can hear it), and then it spends some time charging the 12V battery. Presumably it does this charging as fast as possible, but there may be limits to how fast they can charge the AGM battery without degrading it. Due to other parasitic losses in idle mode (as you say, at least 150W), these recharges in idle mode dominate the vampire losses, as you say. The parasitic losses in idle mode are things like the car computer (perhaps dominant - no idea), a pump - apparently for cycling coolant, the heater on the windshield camera cluster, the cameras, the parking sensors, etc. (Last I checked with a thermal camera these were all on in idle mode.)

your range loss is likely to shift down to closer to 1 mile per day.

For extended periods, I haven't found this to be the case. Vampire loss can really only be measured and quantified over multiple day periods. The various people I know who have checked it consistently see 3-4 miles per day (nearly exactly what Tesla says to expect). There are claims that turning off a bunch of features (no data sharing, no cabin overheat protection, etc.) can help, but I've personally tried this and haven't had any luck having any improvement (though I will still do them in a situation where I really want to minimize drain). YMMV of course. And of course over time Tesla may make small tweaks and improvements to the drain. I haven't checked my losses over a greater than 4-day period for a few months (it was about 4 miles per day last I checked).

I would assume the parasitic losses will be no different in the SR/SR+, so for those vehicles the losses will be more like 1.2-1.5% per day rather than 1% per day. We'd need owner verification of that of course. The lower capacity vehicles are an incentive for Tesla to reduce any unneeded drain, hopefully.

 

[srs5694]

your range loss is likely to shift down to closer to 1 mile per day.

For extended periods, I haven't found this to be the case. Vampire loss can really only be measured and quantified over multiple day periods.

I based my statement on a few times when I've parked my car for over 24 hours and seen very little range loss. (Periods range from 1.5 days to 3.5 days; I have yet to park it for longer than that.) These have averaged about 2 miles of loss per day, but when I refrain from using the Tesla app for a parking session of over a day, the range loss is usually under 2 miles per day. In a quick perusal of my TeslaFi data, the record is a 41-hour period with 1.31 miles of loss (0.77 miles of range loss per day). That one's unusual because the car didn't wake up on its own. Over a period of more than a day, the car is likely to go from sleep to idle at least once for half an hour or an hour, as you say, even if you don't poke at it with the app or in some other way. When that happens, you're likely to lose at least half a mile's range, and often more than that, on top of the baseline sleeping range loss.

 

[AlanSubie4Life]

I based my statement on a few times when I've parked my car for over 24 hours and seen very little range loss. (Periods range from 1.5 days to 3.5 days; I have yet to park it for longer than that.) These have averaged about 2 miles of loss per day, but when I refrain from using the Tesla app for a parking session of over a day, the range loss is usually under 2 miles per day. In a quick perusal of my TeslaFi data, the record is a 41-hour period with 1.31 miles of loss (0.77 miles of range loss per day). That one's unusual because the car didn't wake up on its own. Over a period of more than a day, the car is likely to go from sleep to idle at least once for half an hour or an hour, as you say, even if you don't poke at it with the app or in some other way. When that happens, you're likely to lose at least half a mile's range, and often more than that, on top of the baseline sleeping range loss.

It's interesting that there is such variability (unless it has improved a lot recently). I know two people who have done extended 1-week to 3-week tests without any 3rd party apps, and they were right around the 3-4 miles per day. It is warmer now, software has changed, etc...so there are reasons to think it may actually now be lower...but I haven't had an opportunity to check it.

I happen to use Tesla Stats app, so I don't bother to pay attention to the number it reports (the methodology is fine if it captures all the data, but it tends to lose information in my particular situation). If were doing a test, I would not rely on the TeslaFi data for reporting results. Admittedly, I don't know anything about TeslaFi's methodology, but I know that with Stats it won't always capture the losses for particular periods - it is not a continuous record of every single sleep period. Part of this has to do with occasionally poor LTE connection where it is parked at work, but I think there are other ways data can be lost as well. So if you rely solely on the TeslaFi data...I would be skeptical about the results. That being said, when I've left it at home for long periods, the Stats data has been accurate and generally matched what I observed.

If you happen to take a one-week trip or something, just take a picture of the miles before and when you come back, if you are curious about the drain, and to validate the TeslaFi data. It would be encouraging to see a true 1-2 mile drain per day over a week period.

 

[Wennfred]

While parked at home or in the garage, turn OFF the following:
1. Keep Climate On (off)
2. Cabin Overheat Protection (off)
3. Sentry Mode (off)
4. Data Sharing (no/no)
5. TeslaCam (off)

With these off I have no Drain. Data Sharing is a big drain. Give this a try and write back.

Fred

 

[TexasEV]

While parked at home or in the garage, turn OFF the following:
1. Keep Climate On (off)
2. Cabin Overheat Protection (off)
3. Sentry Mode (off)
4. Data Sharing (no/no)
5. TeslaCam (off)

With these off I have no Drain. Data Sharing is a big drain. Give this a try and write back.

Fred

Data sharing is how autopilot and full self driving improves for everyone. Please don’t turn it off to save a few cents worth of electricity.

 

[mswlogo]

My last charge was completed with 217 miles of range. I now sit at day 5 with 133 miles left. Tesla last charge states 72.7 (73) miles, 14 kWh, and a 191 Wh/miles. So, it appears that I have lost 11 miles due to vampire drain in the past 5 days which is a little over 2 miles a day. (217 - 133) - 73 = 11.

Does this sound about average to you?

Calculation and results look good to me.

 

[jkoya]

Idle mode is also the only way the car has to recharge the 12V battery from the sleep period drain (drain in sleep mode is just a few watts, less than 6-7W I think - works out to a bit less than 1 rated mile per day for sleep drain). So it is required to transition to idle mode periodically, there is no avoiding it, even if you never check the car status. The HV contactors have to close (you can hear it), and then it spends some time charging the 12V battery. Presumably it does this charging as fast as possible, but there may be limits to how fast they can charge the AGM battery without degrading it.

Apologize in advance if this is a stupid question - would using a battery tender that keeps the 12V battery at optimal storage voltage decrease the amount of times the car goes from sleep mode to idle mode ? Just curious since I have an extra battery tender sitting in the garage.

 

[pdx3181]

Apologize in advance if this is a stupid question - would using a battery tender that keeps the 12V battery at optimal storage voltage decrease the amount of times the car goes from sleep mode to idle mode ? Just curious since I have an extra battery tender sitting in the garage.

My understanding that the giant battery keeps the 12v at optimal storage voltage. No need to use a tender.

Others here, smarter than I, may weigh in differently. But that's my understanding.

 

[AlanSubie4Life]

Apologize in advance if this is a stupid question - would using a battery tender that keeps the 12V battery at optimal storage voltage decrease the amount of times the car goes from sleep mode to idle mode ? Just curious since I have an extra battery tender sitting in the garage.

If you do a “battery tender” search you’ll find people have not had a lot of luck. Apparently we don’t know why.

Vampire Drain/Loss Tracking

Not sure whether @rrolsbe ever figured out why the tender did not work. He has other posts on the subject if you search for battery tender.

For me, the tender doesn’t help, since I wouldn’t have access to power when I actually care about vampire drain...so it is an academic question. (Though yes, if a battery tender did prevent the car from waking up, it might well reduce vampire losses to closer to 200Wh/day. So there are some potential efficiency benefits to making it work.)

The car might well wake up for other reasons as well.

 

[AlanSubie4Life]

@jkoya
Just adding to this; another post with some musings on this. As I said, I think there are some mysteries surrounding battery tenders with the Model 3, so I think it's best to view this as informed speculation at the moment:

Understanding the origin and nature of Vampire Drain.

 

[AlanSubie4Life]

While parked at home or in the garage, turn OFF the following:
1. Keep Climate On (off)
2. Cabin Overheat Protection (off)
3. Sentry Mode (off)
4. Data Sharing (no/no)
5. TeslaCam (off)

With these off I have no Drain. Data Sharing is a big drain. Give this a try and write back.

Fred

I've already tried ALL of this (though it was a few months ago when it was cooler). It had zero effect (still 3-4 miles per day). I'd be happy to try it again; perhaps something has changed. I guess I should try as I have a potential trip in a few weeks where minimal vampire drain would be helpful.

 

[AlanSubie4Life]

Calculation and results look good to me.

The calculations aren't correct...you can see the third post. There are some (verifiable) assumptions we have to make to get accurate estimates of the actual vampire loss, but the key mistake is you can't equate driven miles to rated miles use when calculating vampire drain. You have to calculate your energy use and then convert to rated miles. Or convert everything to energy; whatever you prefer.

 

[jkoya]

@AlanSubie4Life - Thank you very much for the links - much appreciated !!

 

[AlanSubie4Life]

While parked at home or in the garage, turn OFF the following:
1. Keep Climate On (off)
2. Cabin Overheat Protection (off)
3. Sentry Mode (off)
4. Data Sharing (no/no)
5. TeslaCam (off)

With these off I have no Drain. Data Sharing is a big drain. Give this a try and write back.

Fred

I've already tried ALL of this (though it was a few months ago when it was cooler). It had zero effect (still 3-4 miles per day). I'd be happy to try it again; perhaps something has changed. I guess I should try as I have a potential trip in a few weeks where minimal vampire drain would be helpful.

I've started this experiment again. Did all of the above, and also changed my Tesla password to break the link to the app. Left my car Wednesday afternoon at 2PM, at 247 miles. I'll check it tomorrow morning and see how it's doing! As I said, last time I tried this it didn't help, but maybe things have changed! I'd be pretty happy with 245 miles, 2 miles loss, in 40 hours, when I check tomorrow. We'll see!

I unplugged my TeslaCam for this - have you found that simply turning it off by pressing and holding the icon is sufficient?

 

[Wennfred]

I unplugged my TeslaCam for this - have you found that simply turning it off by pressing and holding the icon is sufficient?

Yes, just turn it off at the screen.

Fred

 

[AlanSubie4Life]

Yes, just turn it off at the screen.

Fred

Fred, thanks for the tips. Guess we are kind of off-topic from the original thread so after this if any updates maybe I will post in the big vampire drain thread. Definitely seems like these changes result in some improvement vs. the last time I tried this experiment.

“Keep climate on” set to off
Sentry off
Overheat protection off
No Data Sharing
Teslacam off
Apps disabled.

Did not enter the car. Garaged. 70 degrees. Was in vicinity periodically with the phone key. Not plugged in.

67 hours, went from 247 rated miles to 244 rated miles. ~1 mile per day. Without these changes I was at more like 3-5 miles per day, without any actual overheat protection/sentry mode use/climate use.

And it even woke up at some point to get a software update! Might have been less otherwise.

So your impression is data sharing is the biggest specific draw? Any specific data on that? (Obviously sentry/climate would be bigger, but compared to Teslacam, apps, etc.)

Do you run an app at all and still achieve the low drain numbers? I am going to try re-enabling just that next I guess. See whether similar results are achievable.