Pretty much every electronic device in our home, from microwaves and televisions to laptops and game consoles, don’t actually “shut down” when we hit the power button. They go into a “standby” mode, which enables faster restart time, but also uses electricity. One estimate places parasitic drain costs at up to $10 billion annually in the US, or $32 per person.
Parasitic drain also occurs in every automobile newer than 1980, keeping clocks running, computer memory, radio memory and more. The modern automobile has computer systems for nearly every component in the vehicle, and when the engine is shut off and you leave the car, these little parasites still drain the battery.
The new Tesla Model S is no different, but being an electric vehicle [EV], the Model S isn’t a good place to find parasitic drain. Currently, for every day that a Model S is parked, it loses up to eight miles of range, or 2.6% of the 80kWh pack. Park the 40kWh Model S for a month and it will be stone dead.
Fortunately, Tesla Motors has developed a software update that Model S owners are going to want to maximize their range. The new software will shut down more systems in the Model S when you shut the car down, Tesla Motors’ new “Vehicle Sleep” feature, reducing parasitic draw.
The startup sequence starts when the vehicle detects the key, so owners have to remember to keep the key away from the car when it is parked, such as in a garage. Drivers also may notice a slight lag in startup time compared to before, but the 16 miles they lost over the weekend will certainly be appreciated.