Owners of other Mitsubishi vehicles such as the Outlander Sport, Eclipse Cross, Mirage, Mirage G4, Lancer, ASX, Montero Sport, Pajero, Xpander, Strada and RVR may also find these DIY instructions to be helpful.

The compatible replacement coin cell (also known as a "watch" or "button) battery is part number CR2032 which is available from various manufacturers such as Panasonic, Energizer, Duracell, Sony, Maxell and GE.

The only tool needed to access and replace the battery is a small flat head screwdriver such as from a precision screwdriver set (also known as a "jeweler's screwdriver set") or a small plastic pry bar tool.

The first step is to turn over the fob and locate the black plastic sliding switch situated just above the top of the Mitsubishi logo.

Pull the ignition key out of its slot in the fob housing.

Set the metal key aside in a safe place.

Locate the very small notch on the bottom edge of the fob housing near the red plastic "Panic" button.

Very gently pry apart the two halves of the fob assembly.

You may need to remove and reinsert the screwdriver into several locations along the edge of the fob to fully separate the top and bottom pieces.

Try to avoid damaging the red silicone rubber gasket that ensures the fob is water resistant.

Set the rear cover of the fob aside in a safe place.

Try to avoid bending the metal electrical contacts, scratching the green circuit board or breaking the black plastic retaining clips on the edges of the battery holder.

The OEM (original equipment manufacturer) coin cell battery in the "smart" fob for this 2020 Outlander SEL model was a Panasonic CR2032.

Don't be concerned if the original battery is covered in dielectric grease from the factory.

Gently insert the new CR2032 battery into the socket.

Try to avoid breaking the small black plastic retaining clips.

Make sure the new battery is fully seated in the holder.

Line up the rear cover with the fob housing.

Gently snap together the two halves of the fob.

Make sure the front and rear of the fob are flush together at every edge with no part of the red silicone rubber gasket visible.

You should feel or hear the ignition key "click" securely into place.

To test the new battery, stand near your SUV and press the "Unlock" or "Lock" buttons.

If the new battery is working properly, you should see the parking lights flash and hear the door locks opening and closing.

Be sure to write the battery change in your vehicle's service records.

Note - Just changing the battery should not clear the original programming from the factory. You should not have to reprogram the key fob.

Please check out all of the 2014-2021 Mitsubishi Outlander DIY Repair & Maintenance Guides.