The 12V battery drain is arguably the most well-known issue affecting the Polestar 2. Unlike the main high-voltage battery that powers the drivetrain, the 12V battery handles auxiliary systems — door locks, infotainment, lighting, and the computers that wake the car up.
Symptoms
- Car won't unlock via key or app
- Blank or unresponsive center display on entry
- "12V Battery Low" warning in the driver display
- Car won't shift out of Park
- Complete inability to start or precondition
What Causes It
The Polestar 2 runs multiple ECUs (electronic control units) that can stay partially awake even when the car is off. Several known triggers include:
- OTA update failures that leave modules in a half-awake state
- Third-party OBD-II dongles left plugged in, keeping the CAN bus active
- Sentry mode or cabin monitoring continuously drawing power
- Prolonged periods without driving — the 12V battery is small (around 40Ah) and charges from the HV battery only when the car is "on"
- Software bugs in older firmware that failed to properly manage sleep states
The Fix
- 1.Keep your software up to date. Polestar has pushed multiple OTA fixes addressing sleep-state management. Make sure you're on the latest firmware.
- 2.Unplug OBD-II dongles when not actively using them.
- 3.Drive regularly. If the car sits for more than two weeks, the 12V battery can deplete. Consider a trickle charger if you store the car.
- 4.Schedule service if warnings persist. The 12V battery may need replacement — they degrade over time, and Polestar has updated to improved units in later production runs.
- 5.Emergency jump. If you're stranded, you can jump the 12V battery via the terminals under the hood (frunk). A portable jump starter is a worthwhile investment for any Polestar 2 owner.
Which Model Years Are Affected
This issue has been most prevalent in 2021 and early 2022 builds. Later software updates and hardware revisions have significantly reduced occurrences, though it hasn't been fully eliminated.