2021–2026 Ford Mustang Mach-E
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| Part Name | Part Number | Price | Buy |
|---|---|---|---|
| 12V auxiliary battery (correct group size for Mach-E) | — | — | |
| Battery terminal cleaner | — | — | |
| Anti-corrosion terminal spray | — | — |
💡 Pro tip: Order all parts at once to save on shipping
Follow these steps carefully
Park the Mach-E on level ground, power it fully off through the touchscreen, and move the key fob well away from the vehicle. Open the frunk to access the 12V auxiliary battery compartment. Put on safety glasses and insulated gloves before touching any electrical component.
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Locate the 12V auxiliary battery in the frunk area; it is separate from the large high-voltage traction battery under the floor. Identify the orange high-voltage cables nearby and resolve not to touch them. Remove any covers or trim blocking access to the 12V battery terminals.
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Disconnect the 12V negative (-) terminal first using the correct wrench, then tuck the cable aside so it cannot spring back onto the post. Disconnect the positive (+) terminal second. Removing negative first prevents accidental shorting if the wrench touches bodywork.
Video at 2:00
Remove the battery hold-down clamp or bracket securing the auxiliary battery. Lift the old battery straight out, keeping it upright to avoid spilling acid. Note the battery's group size and terminal orientation for the replacement.
Video at 3:00
Clean the cable terminals and the battery tray with a wire brush and terminal cleaner. Set the new 12V battery into the tray in the same orientation and reinstall the hold-down clamp securely. A loose battery bounces and cracks its case on rough roads.
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Connect the positive (+) terminal first and tighten it snugly, then connect the negative (-) terminal last. Apply anti-corrosion spray to both terminals. Confirm both connections are tight by gently twisting; they should not move.
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Power on the Mach-E and check that all systems boot normally with no 12V or charging warnings. Perform the battery management reset procedure through the vehicle settings if required for your model year. The job is complete when the car starts reliably and no fault messages appear.
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Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
