Normally, a new car battery does not need to be charged--it is already fully charged. However, if it is necessary to charge a new car battery, you do not need to follow any special procedures. Just follow the procedures required for safely charging any car battery--regardless of age. Always wear protective eye goggles and gloves whenever charging a battery and never allow any of the corrosive residue around the poles of the battery to come into direct contact with your skin. Never smoke or allow an open flame near a battery because this could cause an explosion.
Clean the battery posts if corrosion is on them. Put 2 tbsp of baking soda in a small container and then add enough water to make a thin paste. Brush this paste onto the corrosion (it may bubble and fizz) and wash off with clean water.
Remove the plastic caps over the battery cells unless your battery is maintenance-free and the caps are non-removable. If the caps are removable fill each battery cell with distilled water (never tap water) until the tops of the plates are just covered. Do not overfill. Replace the caps after filling. If your maintenance-free battery shows a red light, then the battery must be replaced, not charged.
Remove the cables connecting the battery to the vehicle. Use a small crescent wrench or box-end wrench to loosen the nuts around the battery connectors and loosen the connectors. Remove the red (+) wire first and then the black (-) wire. Connect the red (+) charger wire to the red (+) post of the battery. Twist the connector slightly to ensure a good connection. Connect the black (-) charger wire to an exposed metal part of the engine block. Twist this connector slightly to ensure a good, solid connection.
Move the charger as far from the battery as the wires allow it to go and then plug it in. Set the charger (if settings are available) to the 12-volt setting at 6 to 12 amps, assuming your vehicle has a 12-volt battery. If your charger only indicates high or low charging, select high for automobile batteries, or low for motorcycle batteries.
Unplug the charger and remove the red (+) wire from the battery and then remove the black (-) wire from the vehicle's frame after six hours unless your charger automatically shuts off when the charge is complete. Always unplug the charger first, and then remove the battery cables.
Reconnect the car's battery cables. Connect the red (+) cable first and then the black cable. You will need a small crescent wrench or a box-end wrench to tighten the battery cables.
Start the car and allow it to run for 20 minutes or drive the car for approximately three miles to ensure that the battery has a good charge.
If the battery discharges frequently then the root cause of the problem must be discovered and remedied--simply recharging the battery over and over is not the answer.
Keep your face away from the battery as much as possible. Do not allow other people around the vehicle while the battery is being charged. A new battery can be charged outside the car, following the same procedures. Always charge a battery in a well-ventilated area.