Honda Civic 2021 Owner's Manual page 560

Charging the Battery
Disconnect both battery cables to prevent damaging your vehicle's electrical system.
Always disconnect the negative (–) cable first, and reconnect it last.
* Not available on all models
uuBatteryuCharging the Battery
1Battery
When you find corrosion, clean the battery terminals
by applying a baking powder and water solution.
Clean the terminals with a damp towel. Cloth/towel
dry the battery. Coat the terminals with grease to
help prevent future corrosion.
When replacing the battery, the replacement must be
of the same specifications.
Consult a dealer for more information.
The indicators for the Adaptive Cruise Control (ACC)
with Low Speed Follow, Road Departure Mitigation,
Vehicle Stability Assist TM (VSA®) system, Vehicle
Stability Assist TM (VSA®) OFF, Low Tire Pressure/TPMS
and Collision Mitigation Braking System
may come on after re-connecting the battery. Drive a
short distance at more than 12 mph (20 km/h). The
indicators should go off. If they do not, have your
vehicle checked by a dealer.
*
TM (CMBS TM )
559