The ‘vampire drain’ reference place

[Mike]

The 3 most important things in real estate are location, location, location. I believe the 3 most important things about Tesla vampire drain are temperature, temperature, temperature. Be careful about applying losses people are reporting now to what you will get in the dead of winter in Canada.

Agreed.

That said, @Wooloomooloo info shows a location in Brooklyn, NY and @slasher016 shows his location in Cincinnati OH.

 

[Wooloomooloo]

Agreed.

That said, @Wooloomooloo info shows a location in Brooklyn, NY and @slasher016 shows his location in Cincinnati OH.

We've had a few days of temperatures in the early 20's (that's about -7 Celsius) and it didn't make too much difference compared to 30's and 40's during sleep. The biggest impact is definitely in early driving immediately after start, specifically regenerative brakes (which are a lot less effective) and the need for cabin heat.

The former is more an issue in stop start, but you can always adjust your driving style to lift off earlier. The latter I try and keep the cabin heat at about 66, and seat warmer on one bar. If there is sunshine, you get very warm very quickly as the car captures solar heat very efficiently. I'm sure at night you feel the difference.

People all over Norway use EV's all the time, it's colder and darker there than in NY, so I'm sure I'll be fine.

 

[Mike]

Your cabin heat temp is close to mine (18c or 64.5f).

With my setup of keeping the fan at the lowest setting, the low air flow out of the outlets is always toasty.

I keep the seat at 3 bars, mostly because I sit on a memory foam seat cushion and it takes a while to heat soak.

And like you suggest, I have already modified my braking style because of the reduced regen.

 

[webdriverguy]

Your cabin heat temp is close to mine (18c or 64.5f).

With my setup of keeping the fan at the lowest setting, the low air flow out of the outlets is always toasty.

I keep the seat at 3 bars, mostly because I sit on a memory foam seat cushion and it takes a while to heat soak.

And like you suggest, I have already modified my braking style because of the reduced regen.

I need to modify my driving style I keep the heat on 21c and seat heaters on 2 bars 😃

 

[Mike]

I need to modify my driving style I keep the heat on 21c and west heaters on 2 bars 😃

I have 10 years of hybrid driving experience under my belt and old habits die hard

 

[webdriverguy]

I have 10 years of hybrid driving experience under my belt and old habits die hard

Nice. I only have 5 months of EV experience and tons of ICE experience 😄

 

[PNWmisty]

It took me a few posts to realize this was a thread from Nov 2017...

Anyway, I am someone who cannot plug in at home currently, I live in a New York Apt building with no charging access, so when I first got my M3 I was obsessed with vampire drain and checked it every few hours. It's kind of ironic that the more people do to monitor this, the more drain you suffer from. In the early days people were congratulating themselves for installing TeslaFi to monitor the mysterious drain, and yet for many it was actually TeslaFi that was causing the issue. The fact that people still think TeslaFi's new features "put the car to sleep" rather than just not messing with the car's built-in energy conservation features, is testament to how you can create more problems for yourself by being overly-vigilant.

The car is pretty resilient to what it considers normal use, and it's also worth noting that most of the major 'drain' occurs in the first 24 hours of parking, which is a result of the battery cooling significantly, and the car taking time to go into a deep sleep and communicating with Tesla. It's also worth noting (in my experience this is true at least) that the car will often report a lower charge than it really has when the battery is very cold. I've had times when I've gained 1 - 2% of battery charge in the first 5 minutes of driving, despite Whr-useage in the 800's when first setting off.

I rarely use my car during the week, so on Sunday evening I'll often park up with anywhere between 60 and 85% charge (last night I came home with 87% charge) and when I'm ready to head off for a weekend retreat on Friday or Saturday, it's usually lost 3 - 4 % for the week over 5 days.

I would give two pieces of advice to new owners:

1) Change the settings to display state of charge in per-cent (%) rather than range. Psychologically 'range' messes with you as it's far too dynamic, making you paranoid when you see your car lose 2 or 3 miles of range before you've even gone half a mile to the highway. This isn't unique to EV's - my Golf GTI would show 'range' anywhere from 480 miles to 270 miles on a full tank, depending on how I'd driven the last 10 miles.

2) Let the car's energy management systems do what they're supposed to do - i.e. don't install 3rd party apps. I know that's an unpopular statement, but battery technology by its very nature is imprecise and you'll likely spend far too much time fretting about why you lost an extra 3 watt-hours last night, compared to the prior night. I'm also a geek and would love to know every last detail, but I also know that will make me want to micro-manage the car, and it will cause me anxiety. I'm not arrogant enough to think I know better than Tesla's engineers.

Wow! I wish more people brought such realistic perspectives like this. I would characterize much of the vampire drain concerns as borderline hysteria. Granted, I'm sure there have been some instances of OEM software induced vampire drain that were completely excessive but it seems like most people have normal and expected vampire drain.

Then there is the owner who has normal vampire drain but is hyper-concerned because they had one or two instances that appeared to be an excessive drain. I think this happens due to a combination of temperature and usage factors that cause the "remaining range" estimation to provide inaccurate numbers. I think the most common reason this happens is due to the battery monitoring system becoming out of calibration due to a number of charge/discharge cycles without ever taking the battery below 30% (where it can begin to more accurately recalibrate) or over 90% (for the same reason). Owners need to remember the range remaining is only an estimation and it can vary quite a bit under certain circumstances. In other words, not all vampire drain reported by the "Range Remaining" figures is even real energy loss. It could be more appropriately called "phantom drain", not because we don't know what's causing the drain but because the drain is not even real, it's the result of inaccurate battery state guestimates.

 

[FRC]

Before I got my car, I was very concerned about "vampire drain" after reading threads like this one. For about 3 days post-delivery I obsessively monitored my idle SOC to discover, at least for me, no problem. I don't think I've ever experienced anything in excess of 2%/24 hrs. I'm usually under 1%, I think. I really pay absolutely no attention to it any more.

 

[Oyinko]

Hello!

I just bought a P3D and thought it would be interesting to track the vampire drain. The car has 250 miles and is parked in a well insulated garage in San Francisco (average temperature about 65°).

I was on a business trip for 12 days and the car was parked in my garage during that period. I did not check the app and only reported the charging status using the app notifications and later on using the data from my utility provider.

The car was set to maintain a charge of 76% and start charging every day at 11pm. Usually the car was waiting to loose about 2% to start topping it up. On one occasion it did not and waited 71% to start topping it up again.

On average, I lost about 1% per day (3 miles?) and required a total of 111 minutes of charge to maintain battery level over 12 days. All together, the Model 3 pulled 11.76KW from the grid (reported by my utility provider), which represents an average of 0.98KW per day.

In California, with my SuperGreen plan, I pay about $0.14 per KW so that would be a cost of about $4.11 per month.

What do you think of those numbers?
Data: Google Spreadsheet

 

[Frully]

Really cool observations - nice to put data to the rumours. Your google doc doesn't seem to be public as it's not showing in the post.

 

[Oyinko]

Thanks for the feedback. The issue seems to be related to the forum. Click here to access the data.

 

[webdriverguy]

Wow! I wish more people brought such realistic perspectives like this. I would characterize much of the vampire drain concerns as borderline hysteria. Granted, I'm sure there have been some instances of OEM software induced vampire drain that were completely excessive but it seems like most people have normal and expected vampire drain.

Then there is the owner who has normal vampire drain but is hyper-concerned because they had one or two instances that appeared to be an excessive drain. I think this happens due to a combination of temperature and usage factors that cause the "remaining range" estimation to provide inaccurate numbers. I think the most common reason this happens is due to the battery monitoring system becoming out of calibration due to a number of charge/discharge cycles without ever taking the battery below 30% (where it can begin to more accurately recalibrate) or over 90% (for the same reason). Owners need to remember the range remaining is only an estimation and it can vary quite a bit under certain circumstances. In other words, not all vampire drain reported by the "Range Remaining" figures is even real energy loss. It could be more appropriately called "phantom drain", not because we don't know what's causing the drain but because the drain is not even real, it's the result of inaccurate battery state guestimates.

Great point

 

[PaulK]

I agree with your calculations. To properly determine the comparison to driving an ICE vehicle, you should account for this loss/expense.

I wonder what the carbon impact is, in the case of a Model 3 that doesn’t get much use, say only 4,000 miles per year... versus an ICE that doesn’t lose any energy while parked.

 

[radlaw]

Other than the heater, which I turn off at night, what else causes battery drain when car not being used?

 

[Stats App]

Other than the heater, which I turn off at night, what else causes battery drain when car not being used?

Sentry Mode. With Sentry Mode enabled you will lose ~1 mile per hour.

 

[Perscitus]

And a ton of other things, starting with 12V battery, system/accessories, MCU, etc. Polling the car for any data, waking it, etc.

With wifi off, bluetooth off, sentry off, car locked and in deep sleep, you should loose ~1-1.5% SoC per day, especially if garaged and above 35-40F. Anything beyond 3% SoC per day and something is draining the battery pack beyond deep sleep (Sentry, 12V battery recharging, 12v accessory plugged into socket or hardwired with power staying on for an hour or more with recent firmwares).

 

[Ed Woodrick]

Other than the heater, which I turn off at night, what else causes battery drain when car not being used?

It's a computer and a phone. And as you know, your phone will go dead if you don't do anything to it.
To help reduce the "off" power draw, Tesla has designed portion of the car to go into full sleep, while others can only go into partial sleep. When you open your phone app, it starts talking to the car and the phone has to be turned on and the computer on to accept and respond to your phone.
The alarm system stays on, Sentry uses a log more, since it leaves cameras on.
The car monitors the temperatures and turns the AC on if it gets too hot.
The car monitors the 12V battery voltage and charge it from the main pack when needed.


There are a LOT of things that the car does when you aren't using it. You ICE does many of the same things, you just don't realize that when you start it, power and gas goes to the alternator to charge the battery back up.

 

[Stats App]

And a ton of other things, starting with 12V battery, system/accessories, MCU, etc. Polling the car for any data, waking it, etc.

With wifi off, bluetooth off, sentry off, car locked and in deep sleep, you should loose ~1-1.5% SoC per day, especially if garaged and above 35-40F. Anything beyond 3% SoC per day and something is draining the battery pack beyond deep sleep (Sentry, 12V battery recharging, 12v accessory plugged into socket or hardwired with power staying on for an hour or more with recent firmwares).

Right, there are many sources of phantom drain. If you want to compare your phantom drain rate with others, you can use the histogram below. The two vertical lines correspond to the phantom drain rate for my Model S (Gizmo) and my Model 3 (Pride). We turn on Sentry mode on Model 3 when the car is not parked at home. that's why its phantom drain is higher than my Model S.

The graph is from Stats for Tesla App.

 

[BigFelix]

Since I got my Model 3, my ICE car ('91 BMW 850i) rarely gets used - maybe once a week or two. Now it needs to be on a trickle charger to overcome battery drain, even with its two 12V batteries.

 

[Dr. J]

Assuming this is still *The* 'vampire drain' reference place: Bjorn Nyland posted an intriguing video in April 2019 about energy consumption of Sentry Mode. However, the more interesting part to me begins about 3:40 in where he pops out the dash cam USB stick and gets some amazing overnight results. Maybe I'm misinterpreting it, but it looks like the dash cam may be a serious vampire drain culprit. Anybody want to test it?