A Tesla Model 3 owner parked her car in the open and left it unplugged for 32 days in a row. This test gave us some interesting results on how much battery is drained when a Tesla car is left without charging for more than a month.
YouTuber Tesla Joy left her 2018 Tesla Model 3 unplugged when she was leaving for her home country Taiwan from the United States on Nov 14, 2021. She returned to open her car back on 16th December 2021.
Car enthusiasts not familiar with Tesla vehicles might think this would drain the entire battery of the vehicle down — but, this isn’t actually the case.
Joy left her Tesla Model 3 parked in Los Angeles, probably in an open space. The car spent about half November and half December at this location. The average temperature in LA during November varies between 55.6°F (13.1°C) and 71.2°F (21.8°C) and in December it is between 50°F (10°C) and max 64°F (17.8°C) (source: weather-us.com).
The owner turned Sentry Mode off for the entire period of testing as this car surroundings monitoring system drains a lot of battery due to video recording and other functions.
However, she left the HVAC option Cabin Overheat Protection ON. Because this option only keeps activated for 12 hours after the car is parked, the on-screen notice for this option reads as follows:
Cabin Overheat Protection maintains the cabin temperature under 105 F while parked for up to 12 hours after you leave.
No A/C mode consumes less energy but temperatures may exceed 105 F.
This feature does not operate when the battery reaches 20% or less.
It is also highly recommended to not open the Tesla mobile app on your phone as it wakes up the car and results in battery drainage. Joy only opened the Tesla mobile app only 2 times during these 32 days of the battery drainage test.
When the owner of this Tesla Model 3 left the car in the parking lot on 14th Nov 2021, the battery was at 73% state-of-charge (SoC).
On her return after 32 days, that is, on 16th Dec 2021, the car was still at 58% SoC.
The car lost only 15% of battery when parked for straight 32 days without getting charged. This translates to an average daily battery drain of only 0.47%.
The thing to remember is that this is an older 2018 Tesla Model 3 which does not have the heat pump upgrade but still provided great resistance for battery drainage.
Sudden and large losses of battery state-of-charge are a thing of the past, at least for Tesla vehicles — once upon a time, they were called vampire drains. Vampire drains are getting lost in the Tesla history, thanks to the automaker’s constant improvement to vehicle software and hardware.
These results suggest that you can leave your Tesla car parked for even a couple of months unplugged if you have a charged your car at least 70 -80%. This gives Tesla owners the peace of mind when they’re away from their cars on a long vacation.