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 OEM (original equipment manufacturer) "Group Size" is 35 and the part number is Mitsubishi 75D23L.

A few compatible replacement aftermarket Group Size 35 12V batteries with their part numbers include the following: Optima RedTop 8020-164 35, Deka 9A35/85 AGM and Delphi BU9035 AGM.

The tools needed to complete this procedure include a flat head screwdriver, a pop rivet removal tool and a deep well 10mm socket with a 1/4" drive ratchet or a 10mm wrench.

The first two steps are to open the hood and then move to the right (driver) side of the engine bay.

The 12 volt car battery is situated under the engine air intake assembly.

Locate the two round black plastic pop rivet fasteners on the front edge of the air intake just behind the radiator cap.

Use the blade of a flat head screwdriver to gently unlock the two pop rivets by prying up the smaller round button head in the center of each fastener.

Set the two pop rivets aside in a safe place.

Set the air intake assembly aside in a safe place.

Once the air intake is out of the way, you'll be able to access the OEM 12V battery.

Do NOT touch both the negative and positive battery posts at the same time to prevent from being electrocuted.

Attention: Please proceed with caution and at your own risk!

Pull the negative terminal off the "-" battery post.

Wrap the terminal in a small towel and tuck it away below the fuse box to help prevent accidental electrical contact.

Loosen the two nuts by turning them in the counterclockwise direction with the deep well 10mm socket and a 1/4" or 3/8" drive ratchet or a 10mm wrench.

You don't need to fully remove the nuts on the two silver bars. Just loosen them enough until the "J" hooks at the bottom of the bars can be released from their mounting slots.

Carefully detach the front and rear "J" hooks from their mounting slots on the battery tray.

Avoid making contacting with the positive and negative battery posts.

Set the hold down clamp and "J" hook bars aside in a safe place.

Flip open the red plastic cover on the top of the "+" positive terminal.

Pull the positive terminal straight off the "+" terminal.

Tuck the positive terminal back behind the battery by the engine air filter box.

Carefully lift the old 12V battery out of the engine bay.

Rest the battery on the ground and try to avoid dropping or tipping it over to prevent from having battery acid leak out.

Be sure to bring the old battery with you to Walmart or the auto parts store to prevent from having to pay a "core", "disposal" or "recycling" charge.

Clean off any debris on the plastic battery tray so that the new battery will rest evenly on it.

Carefully lower the new battery down into the engine bay.

On this 2020 Outlander SEL, the "+" positive battery post is situated on the left (passenger) side and the "-" negative battery post is located on the right (driver) side of the engine bay.

Push the positive terminal over the "+" battery post.

Tighten the terminal nut by turning it in the clockwise direction with the 10mm socket and a 1/4" drive ratchet until it is snug.

Try to avoid over tightening the terminal to prevent from cracking the battery post which could lead to an acid leak.

Flip the red plastic cover over the top of the positive terminal. The cover should "click" securely into place.

Do NOT make contact with the battery terminals or battery posts.

Reattach the front and rear "J" hooks into their slots on the battery tray.

Push the negative terminal over the "-" battery post.

Check to see if the new 12V battery can be moved, slid or rocked on the tray. If the new battery can be moved, tighten the two nuts on the hold down clamp an extra turn or two.

Reinstall the rear edge of the air intake assembly into the opening in the engine air filter housing.

Line up the two fastener holes in the air intake with the holes on the radiator cover.

Make sure the buttons or "pins" in the center of each pop rivet fastener is in the up and unlocked position.

Push the two fasteners into the holes in the front lip of the air intake assembly.

Push down the pins to lock the pop rivets into place.

To test the new battery, start the engine.

Please remember to adjust the time on the clock and reprogram your favorite radio stations before you start driving.

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

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