12V Auxiliary Battery

This procedure covers the removal and replacement of the 12V auxiliary battery in a 2025 Rivian EDV 500 electric delivery van, including disconnection of high-voltage safety interlocks and battery management system.

Warnings

Tools required

Parts

• 12V AGM auxiliary battery × 1 — Use OEM specification
• Battery hold-down hardware × 1 — Replace if corroded
• Battery terminal anti-corrosion washers × 2 — Use OEM specification

Preparation

1. Park vehicle on level ground and ensure parking brake is engaged
2. Access vehicle touchscreen and navigate to Service Mode under Settings > Service > 12V Battery Replacement to safely disable certain systems
3. Allow vehicle to sit for at least 5 minutes after entering service mode to allow capacitors to discharge
4. Ensure all doors, windows, and cargo area are closed to prevent lock-out after battery disconnection
5. Have radio security code and window calibration procedure available as these will need to be reset
6. Verify replacement battery matches OEM specifications for group size and cold cranking amps

Procedure

1. 1

   Access battery compartment
   Open the hood and locate the 12V auxiliary battery in the front left corner of the vehicle bay, behind the driver-side headlight assembly. The battery is housed in a protective enclosure with a black plastic cover secured by Torx screws.
2. 2

   Remove battery compartment cover
   Using the T30 Torx driver, remove the four screws securing the battery compartment cover. Lift the cover away from the battery box and set aside. Note any wiring harnesses or clips attached to the cover and disconnect them carefully.
3. 3

   Disconnect battery management system connector
   Locate the gray battery management system (BMS) connector on the positive terminal side of the battery. Press the red locking tab and pull the connector straight up to disconnect. This sensor monitors battery health and must be disconnected before terminals are removed.
   ⚠Do not pull on wires; use the connector body to remove. The BMS connector contains delicate pins that can bend if mishandled.
4. 4

   Disconnect negative battery terminal
   Using the 10mm socket, loosen the negative (black) terminal clamp bolt. Remove the bolt completely and carefully lift the terminal clamp off the battery post. If stuck, use a battery terminal puller to avoid damaging the post. Tuck the negative cable away from the battery to prevent accidental contact.
   ⚠Always disconnect negative terminal first to prevent short circuits during the procedure.
5. 5

   Disconnect positive battery terminal
   Using the 10mm socket, loosen the positive (red) terminal clamp bolt. Remove the bolt completely and carefully lift the terminal clamp off the battery post. Cover the positive terminal with a shop towel or insulating material to prevent accidental grounding.
6. 6

   Remove battery hold-down bracket
   Using the 13mm socket, remove the two bolts securing the battery hold-down bracket at the base of the battery. The bracket spans across the top of the battery. Lift the bracket straight up and remove it from the battery compartment. Inspect the bracket for corrosion or damage.
7. 7

   Remove auxiliary battery
   Carefully lift the 12V battery straight up and out of the battery tray. The battery weighs approximately 45-50 pounds. Note the orientation of the battery terminals for proper installation of the replacement. Inspect the battery tray for corrosion, debris, or moisture.
   ⚠Use proper lifting technique to avoid back injury. The battery is heavy and awkwardly positioned.
8. 8

   Clean battery tray and terminals
   Clean the battery tray with a baking soda and water solution if any corrosion is present. Rinse with clean water and dry thoroughly. Use a battery terminal brush to clean both positive and negative cable terminals, removing any corrosion or buildup. Ensure all surfaces are clean and dry before installing new battery.
9. 9

   Install new auxiliary battery
   Place the new 12V battery into the battery tray, ensuring the positive terminal is on the same side as the original battery (typically passenger side). Lower the battery fully into the tray and verify it sits flat and level on the mounting surface.
10. 10

    Install battery hold-down bracket
    Position the hold-down bracket over the top of the battery, aligning the mounting holes with the threaded inserts in the battery tray. Install the two 13mm bolts and tighten securely to prevent battery movement. The bracket should firmly secure the battery without deforming the battery case.
11. 11

    Connect positive battery terminal
    Remove any protective covering from the positive terminal. Apply a thin coat of dielectric grease to the battery post if desired. Place the positive (red) terminal clamp onto the positive battery post, ensuring it is fully seated. Install and tighten the 10mm bolt securely. The connection should be tight enough that the cable cannot rotate on the post.
    ⚠Always reconnect positive terminal first when reinstalling to minimize short circuit risk.
12. 12

    Connect negative battery terminal
    Apply a thin coat of dielectric grease to the negative battery post if desired. Place the negative (black) terminal clamp onto the negative battery post, ensuring it is fully seated. Install and tighten the 10mm bolt securely. The connection should be tight enough that the cable cannot rotate on the post.
    ℹ️You may observe a small spark when making final contact with the negative terminal. This is normal as the vehicle systems initialize.
13. 13

    Reconnect battery management system connector
    Align the BMS connector with the socket on the positive terminal side of the battery. Press the connector straight down until you hear a click, indicating the locking tab has engaged. Gently tug on the connector to verify it is fully locked in place.
14. 14

    Verify battery voltage and system initialization
    Using a multimeter, verify battery voltage at the terminals reads between 12.6-13.2 volts for a fully charged battery. Wait approximately 2 minutes for vehicle systems to initialize. The instrument cluster and touchscreen should power up automatically.
15. 15

    Reinstall battery compartment cover and exit service mode
    Reconnect any wiring harnesses to the battery cover. Position the cover over the battery compartment and secure with the four T30 Torx screws. Access the vehicle touchscreen and exit Service Mode. The vehicle will perform a brief self-check of all systems.

Reassembly

1. Ensure all battery connections are tight and corrosion protection is applied
2. Verify battery compartment cover is fully secured and all fasteners are tight
3. Check that no tools or parts have been left in the engine compartment

Verification

• Turn on vehicle accessories (lights, HVAC, radio) to verify 12V system functionality
• Check instrument cluster for any battery-related warning lights or fault codes
• Verify the touchscreen displays battery status and shows the 12V system charging properly
• Test all power windows and recalibrate as needed using the automatic up/down function
• Verify door locks, power mirrors, and other 12V accessories function normally
• Reset clock, radio presets, and any other memory settings as needed
• Take a short test drive to confirm proper vehicle operation and system stability
• Use vehicle diagnostics to verify no DTCs related to battery or charging system are present

Related trouble codes on this vehicle

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