How To Deal With A Flat Car Battery

Last Updated: 10/05/2022

A flat battery is surprisingly common but it is also one of the most frustrating things that can happen.

You’ll come out one morning to jump into your car to drive to work, only for it to not start.

Batteries can go flat for a number of reasons.

It can happen after you have left the headlights on for a period of time while the car has been inactive and believe it or not, even the newest of cars sometimes struggle to charge a battery if you’re only making short 5-10 minute journeys every day, such as a local commute.

It’s pretty easy to recognise when your car battery is flat.

When you attempt to turn the car on, you will just get a tell-tale clicking noise when you turn the key.

The ignition will not fire because there is no battery power to do so.

Another good way of identifying if the battery is what is preventing your car from starting is to check the headlights.

If you turn them on but they either do not come on at all, or do so and are very dim, then your battery is flat.

So, what do you do next?

What You Will Learn

Flat batteries in cars have been a problem for many years.

While some modern vehicles now make it less common, sometimes there is little you can do to prevent it if you do not know how or why it happens.

In our guide, we will explain a few reasons as to why it happens, plus we will give you the step-by-step guide to the old-fashioned jump start technique to get your engine firing again.

We’ve set the guide out in the usual way, making it nice and easy to follow:

  • Step-By-Step Guide
  • Video Demonstration
  • Hints & Tips
  • Useful Information
  • Final Thoughts
  • Further Resources

Step-By-Step Guide

So, you’ve jumped in the car only to discover that the battery is flat and there is no way to start it.

It’s so frustrating but still pretty common.

Despite all of the advances in modern cars, flat batteries are still a nuisance.

As we’ve already alluded to, modern cars need to have a way of charging the battery so if you only use your car as a run around for short, slow journeys, then you may be heading for a flat battery as well.

If you do have the inconvenience of this happening to you, here’s what you can do.

Jump Starting – Step-By-Step Guide:

  • Jump starting is a technique of getting vehicles to turn on again with a flat battery and it has been used for decades.
  • You will need two things to perform a jump start.
  • First, a set of jump leads, and second, a friend/family member/neighbour with a car who is willing to help.
  • Before starting, consult your car hand book to ensure that jump starting is okay with your make and model.
  • In some instances, it will not be suitable, and this just won’t be an option.
  • Attempting to jump start a car which shouldn’t be jump started can create more problems.
  • Open the bonnet on your car and position the other car close by with the bonnet open.
  • The leads should be able to reach between the two cars.
  • Ensure all of your accessories in the car are off.
  • This includes headlights, phone chargers, satellite navigation systems and interior lights.
  • You don’t want to use any electrical resource other than what is required to start the engine.
  • First, take your red jump lead and connect to the positive battery terminals.
  • The positive terminal will be marked with a (+). Always start with the dead battery.
  • Next, use the black negative leads. Start with a good battery this time.
  • It should be connected to the negative (-) terminal on the good battery.
  • Next, on the car with the dead battery, connect the other end of the cable to the bare metal of the engine at least 45 cms away from the battery.
  • Next, start the car with a good battery and allow it to run for a few minutes on its own.
  • This is to try and put some charge into the car with the flat battery.
  • After a few minutes, turn off the car and remove the cables.
  • First, remove the black cable from the dead car and then the good car.
  • Second, remove the red positive cable from the good car and then finally remove it from the dead car.
  • If charging has been a success, you will now be able to start the car with the dead battery.

Video Demonstration

Hints & Tips

Using jump leads can be very effective but also comes with dangers.

There are also things you can do to minimise the risk of losing the charge in your battery.

Here are a few hints and tips to help you out:

Wear Eye Protection When Jump Starting:

This may seem a little over-the-top but next time you’re in a hardware store and see some plastic goggles (they will be cheap), grab a pair and put them in the boot of your car.

When jump starting, you can expect to get sparks when connecting cables.

If these go into your eyes, it can be very painful.

Worst still, an approximate one in a million batteries can explode – if this happens to you, wearing eye protection could save your eyesight!

Take Your Car For A Decent Drive:

Batteries can run-down even in the most modern of cars if the car is not doing journeys long enough to put some charge into the battery.

Therefore, periodically aim to take your car for a good drive.

It may be a nice run out somewhere for an hour at the weekend or just a 15-minute cruise up the local motorway every week.

It’s a simple step to keep your batter in tip-top condition.

Never Attempt To Jump Start A Cracked Or Leaking Battery:

Batteries are full of acid.

If you notice a battery is cracked or leaking acid, never attempt to jump start it.

Instead, get it replaced.

Failing to do so can cause catastrophic damage to you and the car!

Useful Information

There are other steps you can take to keep your battery charged.

Buying a set of battery charging cables from your local automotive store is always useful if you do only perform small drives or find your battery running low regularly.

It’s important to be aware of how to correctly and safely remove and install the battery in your car if you are doing this though.

Also, if you have elderly friends or relatives who are needing to charge their battery, offer to do it for them.

It will need removing from the vehicle and car batteries are incredibly heavy.

Make sure you are strong enough, healthy enough and have a good technique to lift these batteries and to avoid injuring yourself.

Final Thoughts

Whether it’s for peace of mind or perhaps to diagnose some issues you have had with your car, many leading UK automotive stores and garages now offer free battery checks.

This allows you to analyse the health of your car battery and may be a particularly good thing to do in the autumn ahead of the winter when some old batteries can really struggle.

Further Resources