I Replaced the Battery and My BMW X5 Won#039;t Start

1. Turn your ignition key in your BMW X5 so you can power electrical devices, but don't try to start your engine. Turn on your headlights and other electrical equipment. Check how bright the headlights are and how fast the heater-fan is turning. If the lights are dim and the heater-fan turns slowly you probably have a discharged battery.
2. Turn the ignition key further and attempt to start your car. If the engine doesn't turn over or turns over very slowly then your battery has little or no power.
3. Check the battery cables are securely connected on the battery terminals. Poor connections mean the power necessary to turn your starter motor can't pass through the connection and gives the same result as if the battery is flat. Undo the battery cables using a wrench then re-tighten them. Try to start your BMW X5. If it won't start, it's not the terminal connections.
4. Get someone to give you a jump-start. Position the other car so the two batteries are close enough to attach battery cables. Use battery cables and attach the positive cable to the other car's positive battery terminal and then connect the opposite end to the positive terminal on your battery. Repeat the process by connecting the negative cable to the negative terminals of the other car, and then to your BMW X5.
5. Turn on the engine of the other car. Increase the revolutions slightly. Attempt to turn on the engine of your BMW X5. If it starts, your battery is dead. If it doesn't start you need to get it checked out by a professional. If it started, run the engine to charge the battery. Go for a short drive then leave your car off for several hours.
6. Check to see if your car starts. If it does your battery is fine. If it doesn't start, your battery isn't holding a charge so you should take it back and replace it.