What is Tesla Phantom Drain or Vampire Drain? Battery Manager

A Tesla is a great investment that saves you money on gas, but it can be frustrating when your Tesla’s battery drains for no reason. This makes charging it more expensive and could damage the vehicle over time. What is Tesla phantom battery drain, and how do you manage it?

Phantom drain happens when a Tesla sits overnight or longer while idle and the battery passively drains. Small degrees of phantom drain is inevitable, but you can reduce it by not using third-party Tesla apps and tweaking certain Tesla settings to improve energy efficiency.

In this article, I’ll be going over relevant info about Tesla batteries, including how to maintain, test, and generally take care of your Tesla battery. I also touch on topics like if it’s bad to drain Tesla batteries, how many miles a typical Tesla battery charge will go for, and more.

What Is Vampire or Phantom Drain? 

When your battery slowly drains for no apparent reason while your Tesla is parked, the culprit is most likely phantom drain or vampire drain. These terms are colorful names for a slow, passive drain on your car’s battery.

While some of the onboard components can cause a phantom drain, the OEM’s app and third-party apps can also drain a small amount of electricity when they interface with your Tesla’s system. If your car remains parked without a recharge over a long period, many of these small energy drains accumulate into a surprisingly large loss of battery.

Stopping Phantom Drain on Your Tesla Battery 

You can’t eliminate phantom drain completely because it’s partly because of the car’s default electronics. Your Tesla will experience a noticeable loss of battery or ‘miles,’ as displayed in your car’s Energy app, especially in extreme temperatures.

To prevent phantom drain in areas with extreme weather, park and store your Tesla in a climate-controlled parking area.

Phantom drain can be very inconvenient if you’re in a location with limited access to a Supercharger or even 240v charging capability. With a regular 120v charger, a Tesla may take days to charge.

This isn’t feasible in all situations, especially with time-sensitive matters like vacations, work, family matters, and more.

Thankfully, it’s fairly simple to prevent and minimize the amount of phantom drain so you don’t have to worry about your battery dying when you least expect it.

Here’s what you can do to reduce phantom drains:

  • Turn on energy saving under the power management screen.
  • Uncheck ‘always connected.’
  • Turn off Smart Preconditioning if it isn’t very cold outside.
  • Always keep your Tesla charging when at home.
  • Avoid apps that connect to your Tesla.
  • Use only the official Tesla app to connect to and interface with your Tesla.
  • If you use TeslaFi, consider revoking its permissions, changing your Tesla password, or uninstalling the app. This app frequently pings your Tesla, potentially causing a lot of drain over time.
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While you can’t completely stop phantom drain in your Tesla’s battery, you can change your settings for the best energy efficiency. For general battery efficiency, you can reduce your A/C or heat usage and keep the car in a climate-controlled setting. Photo: @sayfutdinov via Twenty20

Why Is My Tesla Losing Charge So Quickly?

Teslas naturally lose battery capacity over time, but not much of it. Teslas are expected to retain 90% of their original battery capacity at 200,000 miles. This means you shouldn’t have a rapidly discharging battery, not unless something is wrong. 

You’ll normally lose 1% to 3% or more per day when the Tesla is parked because the systems in the car as well as any Sentry Mode or external apps you have enabled are still running.

Also of note is that Teslas will use energy to heat the battery on a very cold day, and to cool down a battery on a very hot day. Cold days take more energy for the Tesla to warm up the battery versus the car cooling it on a hot day.

In the very cold winter months, this issue can affect your battery’s efficiency by as much as 30%. As a rule of thumb, you should expect lower battery efficiency when it’s cold, and to a lesser degree, when it’s very hot. If you live in extremely snowy winter conditions, make sure your garage has proper heating to avoid battery drainage.

Calculating Your Tesla Battery Degradation

The most accurate way of calculating how much your Tesla battery has degraded is to charge your car to 100%, then drive it until the battery has died according to EPA standards, and compare your numbers. 

EPA standards are what your Tesla’s system uses to show your estimated miles left, not the actual number of miles left. That’s because Teslas can’t adjust for driver behavior and other battery degradation factors. So you have to use the standard as your baseline, and your actual numbers as the result; compare the two to get your degradation rate.

If you get less than 200 miles out of an estimated 300-mile battery charge in normal or warm weather, your battery is likely very degraded. It’s important to conduct this test during warm weather because, in the winter, cold temperatures can make the battery use much more power. Therefore, it may seem like the battery is degraded when it’s not.

Testing Your Tesla Battery Health

From your energy screen, you will need to check three things in order to calculate your Tesla’s estimated battery health. These are your AVG consumption, projected range, and battery percentage. 

How To Calculate Tesla Battery Health

  1. Multiply the AVG consumption by the projected range.
  2. Divide the answer by 1000. The result is your available kWh.
  3. Divide your kWh by your battery percentage using decimals—.27 is 27%, .15 is 15%, and so on.
  4. The final result is your actual available kWh.
  5. Compare it to the estimated number to determine degradation—a large deviation means a high degree of battery degradation.

Again, do not conduct this test in very cold weather, as the results won’t be accurate: the car uses more energy than normal just to regulate the battery’s temperature. To get the most accurate results, you should do this in a warm garage or shady driveway.

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By the way, I wrote a related article about Tesla Batteries – Cooling and Heating. I went into detail and explored all the cooling methods and if Teslas can overheat. Check it out!

How Many Charges Can a Tesla Battery Take?

It’s important to consider how many charges an EV battery will take when deciding if you want to buy one. 

An average Tesla battery will last about 1,500 charge cycles. At normally declining battery levels, this equates to between 300,000 miles to 500,000. This depends on if you have a standard range model or a long-distance model.

For most drivers who don’t drive more than 15,000 miles a year, a typical Tesla battery will operate at 90% or higher capacity for more than 15 years. This is assuming nothing electrical or physical happens to harm the battery or its surrounding wiring.

You may also notice slightly less overall longevity if you live in a very cold area. The constant drain on the Tesla system from warming the battery will eventually reduce the battery’s overall capacity.

I also wrote a somewhat related article about Tesla Model 3 Phantom and How You Can Avoid it. I covered some additional aspects. Check it out when you’re done!

How Do I Extend the Battery Life on My Tesla?

A big way you can improve your Tesla’s battery life is to adopt efficient driving techniques. Driving in certain ways can use excessive amounts of energy from the battery, but it’s crucial to know what you can do to improve your Tesla’s battery life.

Ways To Improve Tesla Battery Life

  • Use regenerative braking as often as possible.
  • Charge your battery daily.
  • Don’t let the battery get too low. Irregular charging can reduce battery capacity.
  • Avoid stop-and-go driving with lots of starts and stops.
  • Avoid driving uphill on an inclined surface.
  • Keep your Tesla in a climate-controlled parking area during hot and cold months.
  • Turn off Sentry Mode
  • Use air-conditioning or heat moderately to drain less energy from the battery.

Should You Leave Your Tesla Plugged In All the Time?

Tesla itself says to leave your Tesla plugged in whenever you aren’t driving it, if possible. Tesla also notes that it’s best to use low-voltage chargers on your Tesla—120v and 240v are the typical choices. The supercharger or 480v charger should only be used when you need to charge fast.

There’s no electrical advantage to letting your Tesla battery drain all the way to low levels before charging it. In fact, leaving the battery charging will help it retain some heat and improve starting. Unlike old-school batteries, you can leave your Tesla charging and the onboard computer won’t allow overcharging to damage your battery.

A big plus when keeping your Tesla at 90% charge or higher is that regenerative braking will activate. It’s a unique way of displacing the energy generated by your brakes and converting it back into electrical charge, prolonging your battery life in the process. 

Regenerative braking comes standard on all new Tesla models as of 2020, instead of optional as it had been. It improves energy efficiency on all Teslas.

Is It Bad To Drain Tesla Battery?

It’s bad to leave Tesla batteries uncharged for extended periods of time. As is the case with many other types of batteries, leaving them dead for many weeks or months can accelerate battery degradation. It means the battery will lose some of its capacity, and won’t last as long.

For the most part, it’s recommended to leave your Tesla charging when parked as often as possible. You may not have a charger at work, but you should be fine as long as you plug it in when you get home.

In this video they have studies phantom drain over a few months and they share a few interesting facts. They’ve developed a few tricks that might prevent phantom drain. Check it out!

How Many Miles Does a Tesla Lose Overnight?

Typically, a Tesla will lose anywhere from 1% to 3% overnight in normal conditions if it isn’t plugged in. This number rises with exposure to extreme temperatures, either hot or cold, and usage of apps that connect to your Tesla.

If you’re seeing phantom drains of more than 5%, you should consult your Tesla’s settings to ensure that energy saving is on and that Sentry Mode isn’t enabled.

Please note that Sentry Mode’s protection may outweigh its power drain in some situations. If you’re in a suspicious place where you don’t feel safe, turning Sentry mode on is probably more helpful than the bit of battery it uses.

How Much Does Tesla Battery Replacement Cost?

According to The Drive, a Tesla Model 3 battery replacement generally runs you about $16,000 if your car is out of warranty. This price includes a couple of items that go with the battery, including a wiring harness and battery coolant.

If the battery has stopped working and you are covered by a warranty (like the 8-year guarantee for a new Model 3), you probably just have to call Tesla and explain the situation.

Sometimes Tesla won’t accept the warranty if it deems that the failure is due to ‘driver error’ or other conditions. For the most part, Tesla only covers manufacturer defects that occur within 8 years of purchase.

Saving Your Tesla Battery While Driving

While driving, there are many things you can do to prolong your driving range and battery life. These are generally driving techniques, although weather plays a role too.

Here are some factors that drain your battery:

  • Making frequent and short trips.
  • Braking a lot, aka ‘stop-and-go driving.’
  • Driving uphill a lot.
  • Very cold weather.
  • Driving at very high speeds.
  • Using heat or A/C.

What’s the Most Efficient Tesla Speed?

There’s no official ‘most efficient speed’ for a Tesla, but Extreme Tech and other enthusiasts have crunched the numbers and come up with a surprising number: 28.7mph or 40kph is the most efficient speed for a Tesla, in terms of pure energy efficiency.

It’s important to realize that you can’t necessarily drive at this speed in all situations; it’s rather slow for a highway or interstate, for example. This figure also doesn’t factor in whether you’re using the heat or A/C, so you can expect less efficiency when using those in your Tesla.


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Erwin Meyer
Erwin Meyer

Thanks for visiting evspeedy.com. The goal of this site is to be a helpful resource for Tesla and EV owners as this is where my passion lies. I was a TSLA shareholder before the hype and still am. I also believe in Tesla’s speedy mission to accelerate the world to a sustainable future.