There is nothing more frustrating than finding the car won’t start. Whether you’ve left your lights on by accident or not used your car in the winter for some time the result is often a dead battery. Fortunately, help is at hand. If you know how to jump-start your car then you can get it up and running in no time. And with many households now having a couple of cars, you won’t need to look too far to find a vehicle to give you some charge. 

What is a Jump Start? 

Jump starting is pretty simple. It’s using the live, healthy battery in one car to provide a charge for the depleted battery in the other. You use a set of jumper cables or leads to pass the electricity needed between the cars, connecting the battery from one to the battery from the other. And in a few simple minutes, the car with the flat battery is up and running.

Getting Good Jump Leads

When it comes to purchasing jump leads it’s a good idea to check out your engine type. With petrol cars, you want 25mm2  jump leads and diesel cars need 35mm2 jump leads. You should check this information when you buy and as the cables will need to stretch between 2 cars, you’ll want to purchase one that’s around at least  3 meters in length. Otherwise, you might find you have to park the car with the live battery a little too close to the car that needs charging. 

An alternative to jump-starting your car from another car is to use a jump starter kit that has its own power pack. Length of leads is not an issue with these, but do make sure you get one that can generate the right amount of current.

Why Do I need Different Cross Sections for My Jump Leads? 

Believe it or not, car batteries carry quite a kick and even though they’re low voltage, they need a lot of current. As any electrician will tell you, it’s not the voltage that’s dangerous, but the current, which is measured in amps.

Because petrol is much more explosive than diesel, it takes less battery power to get it going. Hence diesel cars have stronger batteries and need chunkier cables to carry the current. 

As a rule of thumb, it is always better to buy jump leads that are bigger than you need. If you’re in any doubt, say for instance buying from an online source, then always go bigger rather than smaller when it comes to cable width. 

Using Your Jump Leads to Start the Car 

Using jump leads is an easy process. The last time one of our team members tried it, she told us the most difficult stage was remembering to find the switch to lift open her bonnet. 

Park both cars close to each other, allowing enough room for the cables to reach between the bonnets. Make sure the hand brakes are on and open the fronts of both cars. Once you’re inside the engine simply follow these steps to get the battery charged: 

  • Attach one end of the red cable to the positive terminal on the flat battery (this will usually be bigger than the negative terminal or have a + sign on it). And connect the other end to the positive terminal on the donor battery. 
  • Attach one end of the black cable to the negative terminal on the good battery and then to an earth point such as some metal part of the engine in the car you want to start.
  • Start the good car and get the engine running. Now try to start the car with the flat battery. Within a few attempts, you should find this vehicle engine soon begins turning over and running.

If you can’t get the engine to start like this then you may be looking at a completely dead battery. 

Once You’ve Jump Started the Car

When you’ve managed to get the car up and running, it’s vital that you keep it running to recharge the battery.

The engine’s alternator uses the car’s momentum to generate electricity, which is in turn used to boost the battery’s power levels. Avoid having to use jump leads again by taking your car out for a good journey of around 30 minutes or more to restore the battery to a good working condition.

If you recently passed your licence and lack confidence behind the wheel, it can be a good idea to get someone to follow you with jump leads. This way if you stall and the battery fails to get the car going, you can jump-start it again.  

How do you know if the car battery is dead or dying? 

Sometimes the battery can’t be saved. Look out for the following signs that it could be in need of replacement: 

  • The engine turns over

    – constantly making noise without starting. 

  • You can’t get the lights to come on

    – when trying to start the car. 

  • It works intermittently

    – one day the car starts easily, the next day, even though you’ve driven for miles, it won’t start without jumping. 

  • You’re constantly having to jump-start the car

    – if you’re doing everything right and using the alternator to charge 

When batteries get old it’s time to get rid of them. However, take care as car batteries are full of toxic materials that are harmful to you and the environment. Many shops will take the old battery off your hands for recycling. Never throw batteries away with household waste, take them to a special centre, such as your local recycling centre for processing. 

Our Final Word 

If you do find your battery is regularly running out of power then it may be time to look for a replacement. You’ll be better off going for a new unit instead of hoping that endless charging runs to power up the battery after numerous jump-starts. Even though it might cost a bit to replace, you can probably fit it yourself and think about all the time and effort you’ll save. 

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