How to Jump Start a Dead Car Battery on a BMW

1. Pull the working vehicle up to the dead-battery BMW. Do not let the two cars touch, but make sure they are close enough for the cables to reach under each car's hood without becoming taught.
2. Open both hoods and keep the jump-start vehicle on. Do not turn it off. In the BMW, remove the key from the ignition, turn off the radio, any heat or air-conditioning controls or interior lights that are in the 'on' position and close the door. Doing so can eliminate pulling power from the other vehicle before the battery has gained enough power to start again.
3. Clamp the positive jumper cable onto the BMW's positive terminal. Squeeze the handle to open the clamp and release it onto the knob. Do the same to the working vehicle, connecting only the positive part of the battery and the cable -- both are red.
4. Place one of the negative (black) clamps on the negative pole of the booster car. Ground the other end of the negative jumper-cable connector to the BMW by clamping it onto a non-painted metal part of the car, like a bolt or metal piece in the front portion of the engine bay.
5. Open the driver's side door of the BMW to get in and close it quickly. Start the ignition. If the BMW does not come on at first, wait a few minutes before trying again. Once it is started, leave it running.
6. Disconnect the jumper-cables and do not let the cables touch while doing so. Take the clamps off of the BMW and then the jumper-car. Drive the vehicle for about 30 minutes to recharge the battery.