12v Battery

5 Warning Signs Your Tesla 12V Battery Is Dying

Your Tesla has two batteries. Everyone knows about the big one — the high-voltage pack that gives you 300+ miles of range. But there’s a small 12V lead-acid (or lithium in newer models) battery that powers everything else: the computers, door latches, lights, and the contactors that connect the main pack to the drive system.

When this 12V battery dies, your Tesla becomes a very expensive paperweight. The doors may not open. The screen won’t turn on. And the main battery — fully charged — sits there, useless, because the contactors can’t close without 12V power.