The small battery
The one that
strands you
Every electric car still has a twelve volt battery, and a healthy traction pack cannot start the car without it.
At a glance
- It closes the contactors that connect the high voltage pack
- A dead one looks exactly like a dead car
- Cost. roughly 220 to 380 dollars
- Newer Teslas use lithium and cannot be jumped the usual way
Why it matters
The twelve volt system runs the computers, the lights, the door locks and the contactors. The contactors are what connect the high voltage pack. If the small battery is dead, nothing closes them, and a car with a perfectly good main pack strands its owner.
Teslas are different
Teslas built since late 2021 use a lithium ion low voltage battery rather than lead acid. It lasts longer but tends to fail abruptly rather than fading, and it cannot be jumped from an ordinary lead acid source because it charges at a higher voltage. Tesla directs owners to roadside assistance rather than a jump pack.
Buying a Used EV or Hybrid?
Get the battery measured before you pay for it. A PPI Auto inspector tests the pack on the car you are looking at and sends you the numbers. Starting at $225.