How to check if I need a new car battery

Your battery quite literally is the life and soul of your car. Without a fully functioning battery, you’ll literally be on the road to nowhere. If your car won’t start, then there could be something not right with your battery.

Don’t worry, this guide will show you what’s what when it comes to checking your battery life.

There are various different ways that you can test your car’s battery health. Here are just a few of some of the best methods to help you find out whether you might need a new one.

Check the voltage

You can measure your battery voltage by using a voltmeter. Voltmeters can be either analogue or digital and are available from pretty much any good car accessory retailer. They’re simple to use and probably the best way that you can perform a battery check.

First things first, make sure your car is off and so are any accessories that could be draining your battery power, such as the ignition, radio, and highlights.

A good healthy car battery should have around 12.6 volts, any less than this, then you might be a bit worried. So how do you check it? You’ll need to remove the covers on the battery terminals and connect the positive point of the voltmeter to the red battery terminal and the negative point to the black.

If you get a reading of anything less than 11.8 volts, this means that your battery is low in charge and working at around 25%. This means your battery will need charging, sooner rather than later. It’s worth noting too, that if you have a battery that is faulty, then your voltmeter might not be able to deliver and show you the exact results, even if it’s fully charged.

Headlight test

Don’t have a voltmeter? If you don’t, that’s ok because you can check how your car’s headlights react when you turn them on. Turn them on and you find that they’re darker than normal, then this could be a sign that your car battery is low. If you turn them on and you find that they’re getting brighter, this could mean that your alternator is working but that it’s not supplying enough current to the fully charged battery.

If you don’t notice any change in the brightness of your headlights, then all is well and your battery is doing a great job.

Battery indicator

These days our modern cars are fitted with this new component, called the battery indicator. This indicator is basically a cover that is attached to the battery. The way it works is that when you turn on the ignition, an arrow will move to either red or green. As usual, red isn’t a good sign, so if it turns red, the voltage of your battery is low. If it turns green, then your battery is all good. If your battery is completely empty and no longer in use, then you’ll see a black colour.

Power probe

Let’s say for argument’s sake that you don’t have a voltmeter. That’s ok, you can still check your car battery. You can use a performance certificate. The power probe is something that you can use, which has a tip on it, and you can simply tap it on the positive battery pole and the negative. If your battery is all good, then it should have a smashing reading of around 12.2 volts, if not more.

Hydrometer check

What is a hydrometer? This meter can be used to check the degree of acidity in your battery plates. For the best results, if you can get your hands on a hydrometer with a thermometer, then you’ll be sorted. You will if the battery is not working properly, because the acid will be weak.

The main thing is that when you are using a hydrometer to check your battery, is that you were gloves. You’ll be working with battery acid, which can be so dangerous.

All you need to do is open the plate covers on the top of the battery and drop your hydrometer into the first cell. Once you’ve done that, just press the hydrometer cover together. When you release the lid, the electrolyte will flow into the hydrometer and you just need to make a note in your head of the measured value.

If your battery is all good and functioning just as it should, you should expect to see a reading of around 1,260 and 1300 and anything below this, will indicate that your battery is undercharged. If you see anything larger or any discrepancies, then this more than likely means that your battery has some issues.


It’s a good idea to get in the habit of checking your battery voltage every now and then. A good way to get started is by checking the battery and giving it a physical examination, looking for whether it’s got any cracks or bulging sides.

An empty battery can cause you issues and no one wants to be left stranded. If you look and everything appears to be fine, then you can always use a voltmeter to check the voltage. If your battery is weak and not working as it should, you can either recharge it or recycle it and replace it.