These instructions apply to the Tesla Model 3 (2017-2024).
For other models, please choose your vehicle here.
Disconnecting the 12 V battery on your Tesla Model 3 (2017–2024) is something owners occasionally need to do before long storage, before bodywork or work near the airbags, or to recover a car whose low-voltage system has gone flat. This guide covers the 12 V low-voltage battery only. The high-voltage drive battery is a sealed, factory-serviced unit — you never touch it, and you never touch the orange high-voltage cabling. Handled in the right order, the 12 V side is low voltage and safe for an owner to work on, and the car re-establishes its systems on its own once power is restored.
Where the 12 V Battery Is
On the Model 3 the 12 V battery is at the front of the car, reached by removing the front trunk (frunk) tub and the cowl/trim beneath it. Once the trim is out you will see the battery with two leads: the negative (−) on the black terminal, which earths to the body, and the positive (+) on the red terminal, usually under a protective cap. Identify both before you loosen anything.
High voltage: never touch the orange high-voltage cabling. This procedure is only the 12 V battery.
Getting Ready
- Make sure the car is not in READY — power it off from the touchscreen and keep your phone key and any card key away so it does not wake and re-power.
- Wait a couple of minutes after powering off so the low-voltage systems settle before you disturb the terminals.
- Most of your Model 3 settings are tied to your Tesla account and restore automatically, so there is little to note down by hand.
- Wear gloves and eye protection, and have the right tools to remove the frunk trim and slacken the small terminal fasteners.
- Keep to the black and red terminals of the 12 V battery only; the orange cabling is off-limits.
Find the 12 V Battery First
Disconnecting
- Power the car off from the touchscreen (Controls > Safety > Power Off) and wait a couple of minutes.
- Open the frunk and remove the tub and the cowl/trim beneath it to reach the battery.
- Disconnect the negative (−) terminal first, then move the cable aside so it cannot fall back onto the post.
- Now disconnect the positive (+) terminal. If you are working near the airbags, wait a few minutes after disconnecting before you go near them.
Reconnecting
- Reconnect the positive (+) terminal first and secure it.
- Reconnect the negative (−) terminal last and tighten it.
- Check both connections are firm, then allow the car a minute to re-establish its systems before you drive.
What You’ll Need to Reset Afterwards
Because so much lives in your Tesla account, the Model 3 restores most things itself:
- Profile and preferences — most are stored in your account and come back automatically once the car reconnects.
- Tyre pressure monitor — drive the car for a while so it re-stores the current pressures.
- Trim — refit the cowl and frunk tub once the battery is reconnected and the car has powered back up.
- Warning messages — any that appear generally clear after a short drive once the systems have re-synced.
If a Warning Message Stays On or the Car Feels Off
- Re-check both terminals are tight; a loose 12 V connection can throw a range of alerts.
- Give the car a short drive so the systems can re-sync before you assume there is a fault.
- Let the tyre-pressure system re-store its readings over a few miles.
- If the 12 V system went flat in the first place, the battery may be at the end of its life — have it checked.
- An alert that persists has logged a code you can read to see what it points to.
Frequently Asked Questions
Where is the 12 V battery on a Tesla Model 3?
At the front, under the frunk tub and the cowl trim beneath it — completely separate from the high-voltage drive battery.
Is it safe to disconnect?
Yes — the 12 V battery is low voltage and safe for an owner to handle. Never touch the orange high-voltage cabling, which is a sealed, factory-serviced system.
Which terminal do I disconnect first?
The negative (−) terminal comes off first and goes back on last, so the system is dead when you handle the positive and a slipped tool cannot short to the body.
Will I lose my settings?
Most profile settings are tied to your Tesla account and restore automatically when the car reconnects, so you should notice little missing beyond re-storing tyre pressures over a short drive.
Does a new 12 V battery need coding?
Fit the correct 12 V battery type for your build — early cars use a lead-acid unit and later cars a Li-ion 12 V. Match the right type and rating; if in doubt, check your owner’s handbook for the specification your car expects.
Can I jump-start it instead of disconnecting?
If the aim is only to bring a flat 12 V system back to life you can use the car’s low-voltage recovery method rather than pulling the battery. Only disconnect when you are storing the car or isolating the electrics for other work.
If a warning message stays on after reconnecting, look up the code on autodtcs.com.
Independent guide — not affiliated with Tesla. Always follow your official service manual and safety precautions. Read our full disclaimer.