Open the Frunk and Replace a Dead 12 V Battery

Like any car, a Tesla Model Y (2020–2024) has a small 12 V (low-voltage) battery that powers the locks, screens and the frunk release — completely separate from the large high-voltage drive battery. When it fails, the car may not wake and the frunk can stay shut, so there is a specific way to get in and replace it.

Early Model Y cars use a conventional lead-acid 12 V battery; later cars switched to a longer-life lithium-ion low-voltage battery. Both live in the frunk (front trunk), under the liner.

How to open the frunk when the 12 V battery is dead

1. At the front of the car, pop off the front tow-hook cover on the bumper: press the outer edge with both thumbs (around the 1–2 o’clock position) until it releases.
2. Behind it are two 12 V jumper wires — one positive, one ground.
3. Touch a portable 12 V source (a jump pack is ideal) to the terminals, matching polarity.
4. The frunk releases with a pop — lift it and remove the frunk liner to reach the 12 V battery.

How to replace the Model Y 12 V battery

1. If the car still has power, switch it off from the touchscreen (Controls > Safety > Power Off) and wait a couple of minutes.
2. Remove the frunk liner/apron to expose the battery.
3. Disconnect the negative (−) terminal first, then the positive (+), and remove the hold-down bracket. The terminal/bracket bolts torque to about 6 Nm.
4. Fit a replacement of the same type — lead-acid for lead-acid cars, or the correct lithium low-voltage unit — reconnect positive first, then negative, and refit the bracket and liner.

Safety: only work on the small 12 V battery and its wiring. Never touch the thick orange high-voltage cables or the main battery — those are not an owner job. Match the replacement battery’s type and spec to the original; mixing types can need a software update.

Frequently asked questions

Where is the 12 V battery on a Tesla Model Y?
In the frunk, under the liner. It is the small low-voltage battery — lead-acid on early cars, lithium-ion on later ones — not the high-voltage pack.

My Model Y is dead and the frunk won’t open — what do I do?
Pop the front tow-hook cover off the bumper and apply external 12 V to the two jumper wires behind it to release the frunk, then replace the battery.

Is the Model Y 12 V battery lead-acid or lithium?
Early Model Y used lead-acid; Tesla later moved to a lithium-ion low-voltage battery. Check which is fitted and replace like for like.

If a 12 V or electrical warning stays on after the swap, you can look up the fault code on autodtcs.com.