How to Jump Start a Car

Posted on January 23, 2023

Having a flat battery can be a nightmare when you have a busy day planned. Jump starting a car is a quick and handy way to start a car with a flat battery. Be careful when using jump leads as they can cause damage to both cars and people if not used correctly. 

We recommend giving breakdown assistance a call and leaving it to professional mechanics. If you don’t have time to wait for them to come out, here are some tips on how to jump start a car using jump leads. 

What do you need 

  • Pair of jump leads
  • A vehicle with the flat battery 
  • A vehicle with a fully charged battery (Do not use a hybrid or electric car as it can cause damage)
  • Gloves and goggles (Extra safety)

How to Use Jump Leads Safely

jump leadsIt may be your first time using jump leads, so there are a few safety precautions you should take. 




Jump start in a safe environment

  • Remove any clothing that is dangling, such as a scarf. It has the potential to get caught in the moving engine parts, which is a considerable hazard.
  • Do not allow any naked flames, such as a cigarette, near the battery.
  • Remove any metal, such as rings and other jewellery. Do not let any metal touch the car battery. Doing so has the potential to cause a spark and possibly explode the battery. 

Give the battery and jump leads a check

  • Never jump start a battery that looks damaged or is leaking
  • Don’t use damaged jump leads
  • Immediately stop using jump leads if they get hot

Safely removing the jump leads

Never remove the jump leads when the car is still running. If you do, it could cause serious damage to the car.

Guide to jump starting a car

  1. Line up the cars
  • Line up the car with the fully-charged battery so it faces the car with the flat battery. Leave space so that you can open both bonnets. 
  • Turn off all electrical systems/devices. 
  1. Connect red jump lead
  • Put your gloves and goggles on now for extra safety.
  • Attach the red (positive) jump lead to the battery’s positive (+) terminal on the working car. 
  • Connect the other end of the red jump lead to the positive (+) terminal on the flat battery. 
  1. Connect black jump lead
  • Attach the black (negative) jump lead to the negative (-) terminal on the working battery. 
  • Connect the other end of the black jump lead to an earthing point. An earthing point is an unpainted metal on the engine block/chassis. It must be away from both the flat battery and fuel system. Check the car manual to see if your car has a specific earthing point.
  1. Start car with the working battery
  • Keep the engines of both cars off for around 5 minutes. 
  • Start the car with the working battery. Let it run for over 1 minute. 

5. Start car with the flat battery

  • Turn on the engine. If it doesn’t start within a 5-minute time frame, wait and try again. 

6. Allow both cars to run

  • Finally, when the car is running again, allow both car engines to run for 10 minutes. 
  • Remove cables in reverse order. Check the order below to safely remove the cables. Ensure you don’t let the clamps touch metal as you remove them. 

Order of removal

  1. Black lead connected to the car with a flat battery off.
  2. Black lead connected to the car with charged battery off.
  3. Red lead connected to both cars off.
  4. Disconnect all leads from the car.

7. Restart the car

  • After all leads are disconnected, turn on the engine and see if it will start up again. 
  • Leave it running for 20 minutes, then take it on a drive for around half an hour. Only then should you park it. You have now finished the process, and your car battery should now be fully charged. 

start carThat was seven simple steps on how to jump start your car. If unfortunately, your car battery does die, you now know how to get it fully charged in no time.



Jump Start Car FAQs

What should I do after I jump started the car?

If you have successfully jump started the car, you will need to recharge the battery again fully.

To charge the battery, you will have to drive for a duration of 30 minutes. If you have a portable car battery charger, you could use that to top up the charge on your battery. 

How often should I replace a car battery?

Batteries usually last 5-7 years. You should only replace a car battery if it shows any deterioration signs.

If the battery is struggling and is over 5 years old, you should get it checked by a mechanic. 

Why don’t you connect the black jump lead to the negative terminal?

Never connect the black jump lead to the flat battery’s negative (-) terminal. Failure to follow this instruction could result in an explosion. 

How long does it take to jump start a dead battery?

Typically it takes a dead battery five minutes. In harsher weather conditions, this could take up to 30 minutes. 

Can jump starting your car damage it?

It could damage your car if you do not jump start it correctly. For example, putting the clamps on the wrong terminals could damage parts or even cause a fire. 

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