Even a Tesla, as a state-of-the-art electric car, still has them: 12V sockets, also known as cigarette lighters. Very few people probably light cigarettes with them anymore, but they are used all the more frequently for powering practical accessories such as... refrigerators used.
The intriguing question is: Where does the electricity come from? After all, unlike in a combustion engine, there is no longer a classic alternator.
In this article, we explain the basics of the 12-volt system in Tesla vehicles.
Tesla Model Y power supply 12 Volt socket
In theory, Tesla could power all onboard systems directly from the 400V main battery. However, the industry standard for many components such as infotainment, lights, control units, door locks, sensors, and much more is 12 volts. – Those who deviate from this must expect higher costs and increased complexity.
Furthermore, 12 volts is much more compatible with open contacts, such as those found in cigarette lighters. For these reasons, every Tesla has a 12-volt system. The power for this comes directly from the main battery via a 2-3 kW DC-DC converter, which reduces the voltage from 400 to 12 volts.
To prevent the inverter from running constantly, the Tesla 12V battery acts as a buffer; a standard car battery that wouldn't be strictly necessary from a purely technical standpoint. The inverter charges the low-voltage battery, which then powers the vehicle's entire 12V system. If the 12V battery drops below a certain level, the inverter kicks in and recharges it.
Another advantage of this approach: When the Tesla is parked, only this low-voltage system needs to be active (e.g., for essential computer functions, app accessibility, or Sentry Mode); the high-voltage battery can be disconnected via the high-voltage contactors. This drastically reduces energy consumption in standby mode and increases security.
Tesla Model 3 12 volt battery
This basic system architecture is common to all Teslas. – Only newer versions of the Model 3 and Y have a 16-volt network, which combines lower currents with a longer lifespan.
The general functionality remains unchanged, and this system has many advantages. The problem only arises if a malfunction completely discharges the low-voltage battery: Due to the lack of power, the high-voltage contactors can no longer be activated, the main battery remains disconnected from the system, and the Tesla won't move an inch. – just like an internal combustion engine.
Have you ever wondered how many different batteries Tesla uses in its vehicles? exact chemical compositions as well as the advantages and disadvantages of LFP, NMC and Co. You can read more about it on our website.
Have you ever had a problem with the 12V system in your Tesla? Feel free to tell us about it!
