Learn how to jump start a car's battery

Jump start with another car

A dead car battery is a common problem that happens to almost everyone once in a while. You get on the car with your head focused on your future destination, turn the key and... nothing happens. Have you taken care of your car battery maintenance? Have you checked regularly the battery's health? Well, it's probably too late now. What can you do?




In the first place make sure that the problem is actually with the battery. If turning the key you can clearly hear the engine cranking than it's definitely not a problem with the battery. In this case it's better not to insist too much in trying to start the car, as in doing so you might damage the engine and drain your battery's charge. Unfortunately a jumpstart won't help in this context, and you willl have to call a professional. On the other hand if turning the key you hear only a short and fading sound from the engine, all car's lights are dim or absolutely nothing happens, than your battery is dead and a jump start will probably get you back on the road.




The first and most common way to jump start a car is using another car with a working battery. You will need jumper cables to perform this operation. I'm sure you have them in your trunk, right? It's highly recommended to always keep a good set of cables in your car, to help someone else or for your own car. You can buy these cables on amazon, or at any car part shop. Make sure to avoid the cheaper products and instead buy high quality jumpers, thick enough to safely pass current without overheating.


  • Move the two working cars next to each other, close enough so that the cable can reach both batteries. Warning: the cars bodies should never be in contact!

  • Connect one red clamp to the positive terminal (marked with a “+” symbol) of the dead vehicle.

  • Connect the other end of the red cable to the positive terminal of the good car.

  • Now connect a black clamp to the negative pole (marked with a “-” symbol) of the good battery.

  • Close the circuit connecting the other extremity of the black cable to an exposed metallic part of the dead vehicle, for example to the engine block. Make sure that the metallic part is not in direct contact with the positive terminal. Although with modern batteries it would probably be safe to connect the cable to the negative terminal of the dead battery, in general it is better to avoid this practice: sparks generated close to the negative pole might accidentally ignite gases coming from the battery.

  • Start the good vehicle and let it go for a minute or two.

  • Try to turn on the dead car. If it doesn't work you can either wait a few more minutes, or turn off the engine of the working car and repeat the steps above controlling that the cables are firmly placed.

  • Once the dead car starts leave it on idle and disconnect the cables in reversed order: start removing the black clamp from the (hopefully ex-) dead car, disconnect the other terminal from the good battery, next remove the red clamp from the positive pole of the good battery and eventually disconnect the last clamp from the bad battery.

  • Keep the car's engine going for at least 5-10 minutes before turning it off. To play it safe ask the driver of the good vehicle to stay with you until you can safely turn off and than turn on again your car.

  • Drive the car around for another 20 minutes if you can, thus making sure that the battery has enough time to recharge.

If the car doesn't start at all you may have to request assistance from a professional. If the battery keeps dying often you should have the car checked as it might have more serious damages.

But what are you supposed to do if there are no cars around? To help in a situation like that you might want to purchase a battery charger or a battery booster to keep in the trunk.