How to start a car with a flat battery

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How to start a car with a flat battery

Have you ever got into your car, turned the key and nothing happens? The most likely fault is a flat battery, which is a common cause of most breakdowns. This tends to be a frequent case during the winter period, this is because car batteries are working harder to keep you and the car warm.

However, don’t panic! These two starting methods can have you back up and running in no time.

How to jump start your car

This age-old method is very successful and you’ll need the following:

One pair of functioning jump leads
Another car with a powerful, working battery

Inspect battery condition

Do not charge a battery that is damaged, cracked or leaking acid.

Switch off or remove anything in your car that may drain your battery

This will include lights, wipers, heaters, air conditioning and any audio equipment.

Bring the second car over to the car that requires jump starting

Ensure each end of the cables can reach either car with a little slack.

Connect the jump cables

The red cable is positive. Connect either end of this cable to the positive (+) terminals on each battery.

NOTE: Never touch battery terminals with bare hands.

The black cable is negative. Connect this to the negative (-) terminal on the working battery. The other end is to be connected to a bare metal part on the broken-down car, such as the engine mount or the chassis. This earths the car, it is important to keep this end well away from the battery.

If you connect the other end of the black cable to the flat battery it may cause a spark, in some cases this can cause an explosion. It is better to be safe and connect the end to a metal part of the car.

NOTE: Do NOT connect the red and black cables at the same time. Do NOT let the positive and negative connectors touch. This is really dangerous.

Start the engine of the car with the good battery

Approximately 10 minutes of a running engine should be enough to charge up the flat battery.

Try to start the broken-down car

While the second car’s engine is running, try to start the engine of the broken-down car. If start-up fails, allow to charge for a little longer and try again.

NOTE: If the car will not start, this could mean it is time for a new battery. Call a breakdown service.

Disconnect jump leads

Ensure the ends of the cables do not touch to prevent sparking.

Leave the car running for 5 minutes

Once the car has started, leave the engine to run for around 5 minutes before continuing your journey. If possible, take the car to a garage so it can be looked over by an expert.

How to bump start your car

If you don’t have a second car to jump start your car, you may have to bump start your broken-down car. This method works best with two people, or if your car is on a downslope.

NOTE: Never bump start an automatic car. Only use this method if your car is manual.

Leave the ignition on, put the car in second gear and hold the clutch down
Take off the handbrake, and let the car gain some speed

This will happen naturally on a downslope. If this is not the case, have someone push the back of your car.

When the car reaches approximately 10mph, release the clutch

The car should burst into life and will “bump”, hence the name.

NOTE: If this method does not work, you should seek professional help.

Leave the engine running for 20 minutes

If the car successfully starts, leave the engine running for approximately 20 minutes. This will allow the battery to get back up to full charge.

NOTE: Refrain from frequently bump starting your car. This method impacts the catalytic converter that may be fitted. We would recommend buying a new battery if this becomes a common occurrence.