When you jump start a car it should be done correctly, if not then the possibility of battery explosion can occur and will damage the car. Avoid using a frozen battery to jump start a car and the correct battery rating should also be considered.
How to Jump Start a Car?
Step 1. Park a car consist the booster car battery, near the car that has a weak battery and needed to jump start.
Step 2. Make sure that the car A (car with booster battery) and the car B (car about to jump start) has both the parking brake engage. Ensure the gear position is in neutral position if the car is manual transmission and at park (P) position if the car is automatic transmission.
Step 3. Turn off all the electrical equipment on both cars.
Step 4. Connect the jump start cable on both car in the sequence as, positive to positive and negative to negative as illustrated the sequence is (1>>2>>3>>4).
Step 5. Now, start the car A (car with booster battery) and rev the engine up to 2000 rpm, ensure that the gear is in neutral position to avoid accident.
Step 6. Wait for a few minutes then start car B, if the engine does not start turn the ignition "OFF". Wait for 3 to 4 seconds and start the engine again.
Step 7. After jump start of car B, remove the jump start cable. Disconnect the cable in the reverse sequence (4>>3>>2>>1) as illustrated above.