how to replace the 12V battery in Tesla Model S Original (2012-2020)

Tesla Model S Plaid/Refresh (2021-present)

Error Codes

1-2 hours

Time

medium

Difficulty

high

Severity

3 min read

554 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Step-by-step guide to replace the 12V battery in Tesla Model S (2012-2020). Learn symptoms, diagnostic steps, and safety precautions for a successful replacement.

Affected Component

Electrical

Estimated Time

1-2 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the main traction battery before working on the 12V battery to prevent electrical shock.
•Ensure the vehicle is in 'Park' mode and the ignition is off.

Symptoms

•Warning message on the dashboard indicating low battery voltage
•Loss of power to interior lights and accessories
•Difficulty in starting the vehicle or powering on systems
•Frequent error messages related to battery management
•Increased reliance on the main traction battery for auxiliary power

Diagnostic Steps

1
Verify the low battery voltage warning using the vehicle's onboard diagnostics.
2
Inspect the 12V battery connections for corrosion or loose terminals.
3
Use a multimeter to measure the voltage of the 12V battery; it should read around 12.6 volts when fully charged.
4
Check for any additional error codes related to the 12V battery using an OBD-II scanner.
5
Review the vehicle's software for any pending updates that could affect battery management.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•Socket set (including 10mm socket)
•Torque wrench
•Multimeter

Parts Required

•New 12V battery compatible with Tesla Model S

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Symptoms

•Warning message on the dashboard indicating low battery voltage

•Loss of power to interior lights and accessories

•Difficulty in starting the vehicle or powering on systems

•Frequent error messages related to battery management

•Increased reliance on the main traction battery for auxiliary power

Diagnostic Steps

1
Verify the low battery voltage warning using the vehicle's onboard diagnostics.
2
Inspect the 12V battery connections for corrosion or loose terminals.
3
Use a multimeter to measure the voltage of the 12V battery; it should read around 12.6 volts when fully charged.
4
Check for any additional error codes related to the 12V battery using an OBD-II scanner.
5
Review the vehicle's software for any pending updates that could affect battery management.

Solution

1. Preparation

Tools Required:
- Socket set (including 10mm socket)
- Torque wrench
- Multimeter
Safety Warnings:
- Disconnect the main traction battery before working on the 12V battery to prevent electrical shock.
- Ensure the vehicle is in "Park" mode and the ignition is off.

2. Access the Battery Compartment

Open the front trunk (frunk) of the Tesla Model S.
Remove any covering or panels that obstruct access to the 12V battery. This may require unscrewing bolts or clips using a socket set.

3. Disconnect the Old Battery

Using a 10mm socket, loosen the negative (-) terminal first and remove it from the battery.
Next, loosen the positive (+) terminal and remove it from the battery.
Carefully lift the old 12V battery out of its compartment, ensuring not to damage any surrounding components.

4. Install the New Battery

Place the new 12V battery into the compartment, ensuring it is seated correctly.
First, connect the positive (+) terminal to the new battery and tighten it securely with a 10mm socket.
Then, connect the negative (-) terminal and tighten securely.

5. Reassemble and Test

Replace any covering or panels that were removed to access the battery.
Reconnect the main traction battery if it was disconnected.
Start the vehicle and check the dashboard for any warning messages. Use a multimeter to verify that the new battery is functioning correctly.