How To Jump Start a Car Properly and Safely

  • By: Sean Cooper
  • Date: December 13, 2022
How to position cars to jump-start a battery

Until I started working for a car dealership, I’d never had to jump-start a car battery. But dead batteries quickly become a way of life when you have a car lot full of used vehicles, some of which haven’t been driven for a while, especially when the weather is cold. Of course, there can be other reasons why a car battery goes flat, but the immediate solution will almost always be to jump-start the car battery to get you up and running again.

How to Jump-start a car by yourself

If your car, truck, SUV, or van won’t start and you think it’s because the battery is flat, you could call your roadside assistance to help. However, it would probably be quicker and simpler to try jump-starting the battery yourself first. To do this effectively and safely, you’ll need a set of jumper cables and a second driver with another vehicle willing to help out.

  • Position both vehicles facing each other with the park brakes on for safety, close enough for the cables to reach both batteries.
  • Prop both hoods open, locate the batteries, and remove the plastic cover if required
  • Locate the positive and negative battery terminals, and make sure they are corrosion-free
  • Connect one of the jumper cable’s red clamps to the positive terminal of the dead battery
  • Connect the other red clamp to the positive terminal of the other car’s working battery
  • Next, connect one of the black clamps to the negative terminal or the working battery
  • Now take the other black clamp and attach it to some unpainted metal of your vehicle
  • Get the other driver to start the engine of their working car
  • Now you should try to start your engine

If your battery was flat and there are no other issues, you should be good to go. However, don’t forget that after getting your car started with a jump-start, make sure you keep your engine running for around 30 minutes, so the alternator has time to recharge the battery correctly.

Can you jump-start a battery without another car?

You can jump-start a car without jumper cables and another vehicle with a working battery. To do this, you will need a jump pack, which is a portable power pack that you connect to your battery that provides the necessary amperage to crank the engine and start the vehicle.

A jump pack is what garages use, and the pack gets recharged by plugging into the mains electricity supply. To learn more about jump packs, please read this article, where I cover the subject in detail.   

What if a jump-start doesn’t work?

If you have a more serious issue than just a dead battery and a jump start doesn’t work, what do you do next? Here are a few examples of what you might experience:

  • If you hear a clicking noise, but the engine doesn’t start, you may have a problem with your starter motor.
  • Does the vehicle’s electrical system come on? If your lights or radio come on, but the car doesn’t start, you could have problems with the ignition switch, starter motor, a fuse, or your battery could be faulty.
  • Did the jump-start work, but your battery died again shortly afterward? If it did, don’t despair. Try to jump it again and run the engine long enough to recharge the battery.
  • If you try to jump-start your battery, your car won’t start, and none of your electrical systems come on, it’s time to call out a professional.

Common jump-start mistakes to avoid

Before you decide your jump-start efforts are in vain, please ensure you haven’t fallen foul of some common mistakes. These include:

  • Using cheap or damaged cables
  • Leaving the lights, air-con, heater, radio, or any other electrics on when trying a jump-start
  • Turning both ignitions on simultaneously
  • Connecting the cables to the wrong terminals
  • Touching clasps together
  • Ignoring cracks or other damage to the dead battery
  • Trying to connect clamps to dirty or corroded battery terminals

Is your battery up to the job?

Don’t forget that car batteries don’t have an unlimited lifespan. Batteries gradually deteriorate over time and with constant use until they don’t hold enough charge to start an engine anymore. Depending on the usage and environmental conditions, the average lifespan of a car battery is three to five years.

If your battery is more than three years old and you are experiencing problems with it, a replacement is relatively inexpensive and is much better than finding yourself stranded somewhere in a car that won’t start.