There are tons of articles and videos out there already, but all of them are too long.
Requirements: jumper cables and a live car. Order matters.
- Turn off the live car’s engine and remove the key. Make sure the emergency brake is on and the transmission in neutral. Also make sure that your cables are always apart and away from your body.
- Dead car: connect the positive (red) end of the cable to the battery’s positive terminal. The terminals are distinguished from their colors (red for positive and black for negative) and/or their sign (+ for positive, - for negative).
- Live car: connect the other positive end of the cable to the battery’s positive terminal
- Live car: connect the negative (black) end of the cable to the battery’s negative terminal.
- Dead car: connect the other negative end of the cable to a ground, for example a bolt on your hood.
- Keep the cables away from hot components, such as the radiator or the engine.
- Start the live car and slightly rev up the engine every now and then. Do this for a few minutes.
- Dead (now alive) car: disconnect the ground.
- Live car: disconnect the negative terminal.
- Live car: disconnect the positive terminal.
- Dead car: disconnect the positive terminal.
DO NOT confuse the terminals or you will destroy your car’s computer system.