12V Auxiliary Battery

This procedure covers the removal and replacement of the 12V auxiliary battery in a 2024 Rivian EDV 500, including disconnection of high-voltage system and access through the front compartment.

Warnings

Tools required

Parts

• 12V Auxiliary Battery × 1 — Use OEM specification - AGM battery
• Battery hold-down bracket hardware (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Ensure vehicle is powered off and key fob is at least 20 feet away from vehicle
3. Document all vehicle settings, radio presets, and driver profiles using the touchscreen or mobile app
4. Open the front cargo area (frunk) and ensure it remains open throughout the procedure
5. Allow vehicle to sit powered off for at least 5 minutes to allow capacitors to discharge
6. Put on high-voltage insulated gloves before beginning work
7. Take photos of battery connections and routing for reference during reinstallation

Procedure

1. 1

   Access the 12V auxiliary battery compartment
   The 12V battery is located in the front cargo area. Remove the cargo floor panel by lifting it out. Locate the battery access panel on the driver side of the frunk. Remove the Torx fasteners securing the battery access cover using a T30 bit. Set the cover and fasteners aside in a safe location.
2. 2

   Verify system is safe to work on
   Using a multimeter, verify the voltage at the 12V battery terminals reads approximately 12-13V (normal for an AGM battery at rest). Check the high-voltage disconnect status on the vehicle's touchscreen if accessible. Look for any orange high-voltage cabling near the work area and ensure it is properly secured and undamaged.
3. 3

   Disconnect battery management system connector
   Locate the Battery Management System (BMS) connector attached to the top of the 12V battery. This is typically a small multi-pin connector. Press the release tab and carefully disconnect the BMS connector. Secure the connector away from the battery terminals to prevent accidental reconnection.
4. 4

   Disconnect negative battery terminal
   Using a 10mm socket, loosen the bolt on the negative (-) battery terminal (marked with a minus sign or black cover). Remove the bolt completely and carefully lift the negative cable off the battery post. Use a battery terminal puller if the terminal is stuck - do not pry with a screwdriver. Secure the negative cable away from the battery post using a zip tie or tape to prevent accidental contact.
5. 5

   Wait for system capacitor discharge
   Wait a minimum of 2 minutes after disconnecting the negative terminal. This allows the vehicle's electrical system capacitors to fully discharge, particularly those in the airbag and high-voltage control systems. Do not skip this waiting period.
6. 6

   Disconnect positive battery terminal
   Using a 10mm socket, loosen the bolt on the positive (+) battery terminal (marked with a plus sign or red cover). Remove the bolt completely and carefully lift the positive cable off the battery post. Cover the positive terminal with a non-conductive material (electrical tape or rubber cap) to prevent accidental short circuits. Secure the positive cable away from the battery and any metal surfaces.
7. 7

   Remove battery hold-down bracket
   Locate the battery hold-down bracket securing the battery in place. Using a 13mm socket, remove the bolts securing the hold-down bracket. There are typically two bolts threading into the battery tray. Remove the bracket completely and set it aside. Inspect the bracket and hardware for corrosion or damage.
8. 8

   Remove old 12V battery
   Carefully lift the 12V auxiliary battery straight up and out of the battery tray. The battery weighs approximately 40-50 pounds - use proper lifting technique and get assistance if needed. Inspect the battery tray for corrosion, debris, or moisture. Clean the tray with a wire brush and baking soda solution if corrosion is present, then dry thoroughly.
9. 9

   Prepare and install new battery
   Inspect the new 12V auxiliary battery to ensure it matches the OEM specifications (AGM type, correct group size, and capacity). Clean the battery posts with a battery terminal cleaner if needed. Carefully lower the new battery into the battery tray, ensuring it is properly seated and oriented with positive and negative terminals in the correct positions matching the cable locations.
10. 10

    Install battery hold-down bracket
    Position the battery hold-down bracket over the new battery. Thread the 13mm bolts through the bracket and into the battery tray. Tighten the bolts in a cross pattern to ensure even pressure. The bracket should hold the battery firmly without over-tightening, which could damage the battery case. Verify the battery cannot move side-to-side or lift up.
11. 11

    Reconnect positive battery terminal
    Clean the positive battery post and cable terminal with a battery terminal cleaner brush. Remove any protective covering from the positive cable terminal. Place the positive cable terminal onto the positive (+) battery post, ensuring it is fully seated. Install the 10mm bolt and tighten securely until the terminal cannot rotate on the post. Do not over-tighten as this can damage the post.
12. 12

    Reconnect negative battery terminal
    Clean the negative battery post and cable terminal with a battery terminal cleaner brush. Place the negative cable terminal onto the negative (-) battery post, ensuring it is fully seated. Install the 10mm bolt and tighten securely until the terminal cannot rotate on the post. Expect a small spark as the final connection is made - this is normal as the vehicle systems initialize.
13. 13

    Reconnect battery management system connector
    Retrieve the BMS connector and align it with the receptacle on top of the battery. Press firmly until you hear or feel a positive click indicating the connector is fully seated. Verify the connector lock tab is engaged. This connection allows the vehicle to monitor the 12V battery health.
14. 14

    Verify battery installation
    Using a multimeter, measure the voltage at the battery terminals. It should read approximately 12.4-12.8V for a fully charged AGM battery. Check that all connections are tight and properly seated. Verify no tools or parts have been left in the battery compartment. Gently attempt to move the battery to confirm the hold-down bracket is secure.
15. 15

    Reinstall access panels and initialize vehicle systems
    Reinstall the battery access cover using the T30 Torx fasteners. Replace the cargo floor panel in the frunk. Bring the key fob near the vehicle and attempt to unlock it. Enter the vehicle and press the brake pedal while pushing the power button to initialize the vehicle. The touchscreen should power on and may display initialization messages. Allow the vehicle to complete any startup procedures.

Reassembly

1. Ensure all battery terminals are tight and free of corrosion
2. Verify the battery hold-down bracket is securely fastened
3. Confirm the BMS connector is properly seated and locked
4. Replace all access panels and cargo floor covers in the frunk
5. Verify the frunk closes and latches properly

Verification

• Power on the vehicle and verify the touchscreen displays normally without any 12V battery warning messages
• Check that all interior lights, exterior lights, and power accessories function correctly
• Verify the vehicle can shift into Drive and Reverse (high-voltage system should be operational)
• Use the touchscreen to check battery status - the 12V auxiliary battery should show healthy status
• Test the key fob lock/unlock functions and proximity unlocking features
• Verify the vehicle can be powered off and restarted without issues
• Check for any diagnostic trouble codes using the vehicle's service menu or OBD-II scanner
• Reprogram any lost vehicle settings, radio presets, and driver profiles
• If available, perform a 12V battery health test using a battery analyzer to verify proper charging system operation
• Monitor the 12V battery voltage over the next few days to ensure proper charging (should maintain 12.6-13.2V when vehicle is off, 13.5-14.5V when charging)

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