5. Why You'll Need a Jump Start

It's the battery that gives your car the impulse of power to activate the starter and turn over the engine. When the battery no longer holds a charge, the starter won't activate and you'll need a jump start. Usually, this is simply due to an old, aging battery. However, the alternator also plays a key role. It uses power from the engine to recharge the battery once it's operating on its own power. If the alternator is bad, you may find your car dies again very quickly after a jump start - in which case you'll need a tow to your nearest authorized Subaru service center.

4. Things to Try Before a Jump Start

Before you jump start your car, it's a good idea to visually inspect the battery terminal posts. Over time, corrosion can build up on these posts and prevent a good electrical connection from flowing from the battery. And since the jump start will involve these battery posts, if they're dirty, even the jump start may not work. Remove the battery cables and scrape the corrosion off the terminals. Then, hook the battery back up and try starting the car again - just in case it was the corrosion kept your battery from starting the car.

3. Take an Ounce of Prevention

On both your car and the donor car, it's a good idea to turn off any electrical accessories like the lights, stereo and climate control before attempting the jump start. A sudden change in electrical voltage could damage these components if they're actively drawing power when the jump start occurs. It's unlikely, but it's always wise to play it safe, especially when it comes to electricity.

2. Never Hook Up the Negative Battery Terminal on the Stalled Vehicle

To begin, attach the positive (red) battery cable to the positive post on your car's battery. Be absolutely sure which post is which on both cars before proceeding! Next, attach the positive cable to the positive battery post on the donor vehicle. Then, attach the negative (black) cable to the negative battery post on the donor vehicle. But don't attach the negative cable to your car's battery! In rare situations, this could cause an explosion. It's safer instead to find a section of unpainted, bare metal somewhere in the engine compartment and attach the negative cable to that. Or, consult your owner's manual - many modern cars have a designated flat piece of metal specifically designed to be attached to in a jump start.