Keep all sources of flames or sparks away from the battery. The battery generates hydrogen which may explode if exposed to a flame or spark. Do not attempt to start the engine if a dead battery is frozen or if the electrolyte level is low, the battery may burst or explode.
The sequence of starting the engine from the battery of another car:
1. Make sure the booster battery is 12V and its negative terminal is grounded.
2. Check the electrolyte level in each battery cell.
3. If the auxiliary battery is in another car, do not let the cars touch.
4. Turn off all unnecessary electrical consumers.
5. Connect all cables in the exact sequence shown in Figure 120. Connect one end of the cable to the positive terminal first (+) discharged battery, then the other end of the same cable to the positive terminal (+) auxiliary battery. Next, connect one end of the second cable to the negative terminal (–) auxiliary battery and then the second end to the mass, stationary metal point (e.g. to the engine mount) apart from the battery. Do not connect the cable to or near moving parts, as they could be damaged during start-up. Do not connect cable from negative (–) auxiliary battery terminals to negative terminal (–) discharged battery. Do not allow cables to touch anything other than the appropriate battery terminals or proper grounding. When connecting cables, do not lean over the battery.
The sequence of connecting cables when starting the engine from the battery of another car.
6. Start the vehicle engine from the auxiliary battery and leave it running at 2000 rpm-1. Then start the car engine with the dead battery.
If the cause of your battery discharge is not obvious, such as the car's headlights being accidentally left on, you should have your vehicle checked by an authorized HYUNDAI dealer.