Vehicle Jump-Starting procedures as listed below should be followed carefully:
Ensure that vehicle battery and battery for jump-starting have the same declared voltage (say 12V)
Turn off all electrical loads, check vehicles - no part should be touching each other and gear should be in neutral position
Vehicles should have the same terminal earthed, if not, refer to manufacturers' instructions. Make sure that cables are not frayed or damaged.
Carry out the following steps in sequence:
Connect the positive terminal of jump-starting battery to the positive terminal of the stalled car battery - on negative grounded system.
Connect one end of the other cable to the negative (-) terminal of the booster battery.
Connect the other cable away from the battery, to the engine block or car frame of the vehicle to be started.
Make sure cables are away from fan blades and other moving vehicle parts.
After starting, remove cables in reverse order, starting with one connected to engine block or car frame.
If vehicle does not start within 30 seconds, call an auto electrician.
Modern vehicles with electronic management systems should not be jump-started without "protected" jump starter leads. It is necessary to refer to the owner's handbook for jump-starting procedures for such vehicles.