Tesla Phantom Drain: How to Monitor Battery Loss with Tessie
Last Updated: July 29, 2026
In a rush? Open Tessie, go to Battery and select Phantom Drain. Tessie records energy lost while your Tesla is parked, so you can see whether the car is sleeping properly and compare the drain before and after changing settings.
A Tesla losing one or two per cent while parked can be hard to judge from the battery number alone. Temperature changes can move the displayed percentage, while Sentry Mode, climate features or a car that refuses to sleep can use real energy.
Tessie helps because it keeps the parked periods instead of leaving you to remember what the battery showed yesterday. The Phantom Drain view in the Battery section is where I would start. It turns a vague feeling that the car is losing charge into a record you can compare.
See what your Tesla uses while parked
Tessie records idle activity and gives you a dedicated Phantom Drain view in the Battery section. Use my referral link to try it with your Tesla.
What is Tesla phantom drain?
Phantom drain is energy your Tesla loses while it is parked and not charging. The car still has computers, connectivity and battery-management systems running in the background. Some features also keep it awake on purpose.
A small change does not always mean the car consumed that exact amount. Battery temperature and the car's estimate of available energy can alter the displayed state of charge. A repeated pattern across several parked periods matters more than one isolated percentage change.
Where to find Phantom Drain in Tessie
- Open the Tessie app and select your Tesla.
- Open the Battery section.
- Choose Phantom Drain.
- Review the recorded parked periods and the energy lost during each one.
- Compare similar periods before and after changing a setting.
Tessie calls time when the car is not driving or charging an idle period. It logs those periods automatically after you connect the car and enable data logging. You do not need to leave the Tessie app open on your phone.
What the Tessie Phantom Drain view tells you
The useful part is the history. You can see whether the loss happened during a long overnight park, a day at work or several days at an airport. That context helps you decide whether the drain matches the features you left running.
Look at the length of the parked period as well as the percentage or energy lost. Losing one per cent over several days tells a different story from losing the same amount every few hours.
Tessie also records vehicle sleep and idle behaviour. If the car stays awake for long stretches without a clear reason, you have something specific to investigate rather than repeatedly opening the Tesla app to check the battery.
Start with Low Power Mode
If your Tesla has Low Power Mode, enable it first when you want to reduce parked drain. You will find it in the car under Controls > Charging > Low Power Mode.
The setting cuts background energy use and helps the vehicle sleep. It is particularly useful before leaving the car at an airport or anywhere it will sit for several days. After switching it on, use Tessie's next Phantom Drain record to see the difference on your own car.
Why Sentry Mode changes the result
Sentry Mode watches the area around the car, so it consumes energy while parked. A Tessie record showing more drain at a busy car park than on your driveway may be completely consistent with Sentry activity.
Check whether Sentry was active before treating the loss as a fault. If it is safe to test without it, turn Sentry off for one comparable parked period and check the next Tessie result. That gives you a much better comparison than guessing from two unrelated days.
Cabin Overheat Protection and climate use
Cabin Overheat Protection can wake the car and cool the cabin in hot weather. Preconditioning, scheduled departure and climate controls also use energy by design.
Tessie may show greater parked loss on a hot day even though nothing is wrong. Compare weather and settings when you review the record. If you change three features at once, you will not know which one made the difference.
Check whether the car is sleeping
A Tesla should normally settle into sleep after you finish driving or charging. Tessie's guidance says this often takes around seven to ten minutes, although the exact time can vary.
Repeated long awake periods deserve attention. Start with pending software updates, weak Wi-Fi, Summon Standby, accessory power, nearby keys and phones that keep reconnecting over Bluetooth. Update the Tesla app on every connected device too.
Avoid opening vehicle apps every few minutes during the test. Each manual check can wake the car and spoil the parked period you are trying to measure.
Does Tessie itself cause phantom drain?
Tessie is designed to let the car sleep and uses Tesla's current data connections to monitor it. Its idle tracking runs in the cloud, so your phone does not need to poll the vehicle continuously.
Some older Model S and Model X hardware and firmware combinations had an API-related wake issue. Tessie's current guidance points affected cars towards newer firmware and Direct Telemetry. If you have an older car and it never settles, check the current Tessie support advice for that model and software version.
How to run a useful phantom-drain test
- Choose an ordinary overnight period when the car does not need to charge.
- Note whether Sentry Mode, climate protection and Low Power Mode are active.
- Leave the car alone and avoid checking it through other apps.
- Review the completed idle period in Battery > Phantom Drain.
- Change one likely cause and repeat the test in similar conditions.
You do not need laboratory conditions. You need enough consistency to spot a repeated pattern. Two or three comparable nights usually tell you more than watching the battery percentage throughout one evening.
Phantom drain at an airport
Airport parking is where phantom drain becomes more than an annoyance. A feature using a few per cent each day can make the return journey uncomfortable after a long trip.
Enable Low Power Mode, turn off features you do not need and check the expected state of charge before leaving the car. Tessie can monitor the idle period without you constantly waking the vehicle for reassurance.
If you do check during the trip, look at the Phantom Drain history rather than repeatedly refreshing the live vehicle screen. You want to know the trend while allowing the Tesla to remain asleep.
When to contact Tesla Service
Contact Tesla if the car repeatedly refuses to sleep after you have installed pending updates, disabled obvious awake features and ruled out weak connections or nearby keys. A large unexplained loss across comparable Tessie records gives you useful dates and times to describe.
Do not diagnose a failing high-voltage battery from phantom drain alone. Parked energy use and long-term battery degradation are different questions. Tessie has separate battery-health tools for degradation and charging history.
Stop guessing where the charge went
Use Tessie's Phantom Drain history to compare parked periods and check whether your changes are helping the car sleep.
Frequently asked questions
How much phantom drain is normal for a Tesla?
There is no single figure that suits every car and situation. Weather, Sentry Mode, connectivity and software activity all matter. Use several similar parked periods to establish what is normal for your Tesla.
Can Tessie show when the battery loss happened?
Yes. Tessie records idle periods when the car is not driving or charging. Open Battery and select Phantom Drain to review the parked-loss history.
Does opening the Tesla app drain the battery?
Current app behaviour depends on the vehicle and software, but repeated manual checks can wake the car or keep it active. Leave it alone while running a sleep test.
Should I leave Low Power Mode on?
Low Power Mode is the first setting I would enable before a long park. Check which background features it limits on your car, then compare the Tessie records before and after using it.
Is phantom drain the same as battery degradation?
No. Phantom drain is energy used while parked. Degradation is the gradual reduction in the battery's usable capacity over time.
More Tessie battery guides
- Check Tesla battery health at home with Tessie
- Use Tessie to investigate faster battery loss
- Read my full Tessie app review
I’m Steven, founder of MoneyAppReviews. I test money apps, referral programs, and EV tools in real life before I write about them. I drive a 2021 Tesla Model 3 Long Range, use Octopus Intelligent Go for home charging, and regularly track costs, savings, and app performance over time. I focus on practical, evidence-based reviews that help people decide what is actually worth using, not just what pays the highest commission.
