Section 210 (Engine Starting System & Charging System): Battery: Inspection: Appearance

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

Check the battery case, top cover and terminals for dirt or cracks, and perform the following work as necessary.

Clean the battery with water and wipe with a dry cloth.
Apply a thin coat of anti-rust grease on the terminals to prevent corrosion.

Check

Normal → Go to the check item 2.
Abnormal → Replace the battery.