Vehicle Battery Maintenance, Part 2: How to Clean & Protect Your Car Battery from Corrosion. • Apply CRC Battery Cleaner onto disconnected terminals and cable ends. • CRC Battery Cleaner sprays out yellow foam that turns pink when it finds acid. • Let it sit for 1 or 2 minutes to break down corrosion and neutralize the acid. Scrub away the corrosion if necessary. • Keep spraying until all you see if yellow, so you know the acid is fully neutralized. • Apply CRC Battery Terminal Protector to a cl