Hyundai i20 Owner's Manual page 320

Emergency situations
7. Connect the other end of the second
jumper cable to the black, negative (-)
chassis ground of your vehicle (4).
Do not allow the jumper cables to
contact anything except the correct
battery or jumper terminals or the
correct ground. Do not lean over the
battery when making connections.
8. Start the engine of the assisting
vehicle and let it run at approximately
2,000 rpm for a few minutes. Then
start your vehicle.
If your vehicle will not start after a
few attempts, it probably requires
servicing. In this event please seek
qualified assistance. If the cause of your
battery discharging is not apparent,
we recommend that your vehicle be
checked by an authorized HYUNDAI
dealer.
WARNING
Never connect Jumper Cable directly to
the negative (-) terminal of discharged
Battery (Your Vehicle Battery), or an
Explosion may occur.
9-6
Disconnect the jumper cables in the
exact reverse order you connected
them:
1. Disconnect the jumper cable from the
black, negative (-) chassis ground of
your vehicle (4).
2. Disconnect the other end of the
jumper cable from the black, negative
(-) battery/chassis ground of the
assisting vehicle (3).
3. Disconnect the second jumper cable
from the red, positive (+) battery/
jumper terminal of the assisting
vehicle (2).
4. Disconnect the other end of the
jumper cable from the red, positive (+)
jumper terminal of your vehicle (1).