Car Care

9 simple ways to keep your car battery healthy and happy.

Ciara Knight's profile picture
Ciara Knight

There are positives and negatives to having a car battery.

While they power your car, allowing you to get from A to B, batteries can also cause a bit of hassle when they start acting up. But if you put in the effort to look after your car battery, it’ll return the favour and keep you going for as long as it can.

Car batteries are particularly at risk of draining during cold weather, and when they’re unused for a long period of time (during lockdowns, for example).

A healthy battery stays out of your mind, as it should, but an unhealthy one can cause you a lot of issues. Putting in a small bit of effort now can save you time and money in the long run.

We’ve got some top tips to help make sure your car battery stays alive and well.

  1. Check if your car battery is due to be changed.

The RAC advises that most batteries last up to 5 years, but just like the luggage carousel at Gatwick Airport, it’s a case-by-case basis. Some batteries can fail after as little as two years, depending on the conditions they’ve been kept in and how the car’s been driven. It’s worth looking into changing your car battery if it’s been acting up lately, or if it’s edging towards its fifth birthday. The winter months are the most challenging for car batteries, so getting yours sorted in advance will have you one step ahead of the crowd.

  1. Take your car for longer drives to charge the battery.

As well as being bad for the environment, short journeys can put a lot of stress on car batteries. If the car isn’t running for long, the battery doesn’t get enough chance to recharge. So if you find that you’re doing a lot of short journeys, it’s possible that your battery could be in danger of being undercharged. To keep things ticking over, take the car for a decent spin (at least 30 minutes) every so often to give it a chance to charge up the battery fully and balance out the shorter journeys.

  1. If you’re not driving, let your car run for 15 mins once a week.

To keep your battery fit and healthy, it’s helpful to start the car up once a week and let it run for 15 minutes, in a well-ventilated place. Never leave your car’s engine running in an enclosed space like a garage, as this can cause a deadly build-up of carbon monoxide gas. Also, be sure not to leave the car unattended while the engine is running, as opportunists are everywhere – it’s no good having a fully charged battery in a stolen car. To brighten up your 15 minute wait while the battery charges, why not listen to our special By Miles Battery Boost playlist.

  1. Make sure everything is switched off when you park up.

It’s easily forgotten, but doing a quick check on electrics before you get out of the car is a good habit to get into. Make sure all lights, wipers, heaters, sat navs and entertainment systems are fully off, as they can drain the battery next time you start it up. Interior lights are the car’s equivalent of a silent assassin, so always have a look to make sure they’re all turned off before you leave the car.

  1. Consider getting a trickle charger for your car battery.

A trickle charger is a nifty device that keeps the battery charged if the car is going to be parked up for a long time. It slowly adds charge to the battery to stop it from going flat. You can grab one online or in a car accessory shop, and as one of our lovely Twitter followers pointed out, solar-powered chargers exist too.

  1. Make sure your car battery is tightly fastened into place.

A wobbly battery can reduce its lifespan, so it’s a good idea to make sure it’s securely in place with a proper battery clamp. Vibrations can damage the inside of the battery by creating short circuits and that’s not good for battery life. On the other side of things, an over-tightened battery clamp can also damage the battery. The next time you’re at the garage, remind the mechanic to give the battery fixture a once-over so you can be sure that it’s securely in place.

  1. Park your car in a garage or sheltered place, if you can.

Much like a beloved pet, you may want to consider moving the car into a sheltered space if it’s going to be parked up for a while when the outside temperatures aren’t ideal. Cars have to work a little harder to start the engine in the winter months, but similarly, extreme heat during the summer months can be bad business for batteries too. If possible, store your car in a garage or dry place where it’s protected from the elements. (A complimentary blanket and cup of cocoa is optional).

  1. Press the clutch pedal when you’re starting the car.

This takes some of the pressure off the starter motor and the battery when you’re starting the car. It can decrease the wear and tear on the battery, and come in clutch (pun intended) if you’ve got a weak battery to begin with. Putting it into practice is an easy habit to get into and has proven to have a positive (pun also intended) effect on the battery’s life. “I’ve just helped to save a life”, you can think to yourself each time you start up while pressing the clutch pedal. 

  1. Pay attention to warning lights on your dashboard.

It should go without saying, but sometimes there’s a temptation to ignore a warning light on the dashboard until you reach your destination. That’s a pretty dangerous approach, so it’s always best to check out your car’s handbook to see what’s happening before you set off, particularly where the battery is concerned. If you’re still unsure, don’t drive the car. Get in touch with your mechanic for advice before you go anywhere.


On the subject of battery life, if you’ve got a By Miles policy, you’re in luck. We’ll be releasing our newest app feature very soon, and it’s going to make looking after your car battery a little bit easier. 

It’s pretty simple. If your battery starts showing signs of low charge, you’ll get a push notification sent straight to your phone to let you know. Then you can investigate the problem before it becomes a bigger one, so the dreaded nightmare of being faced with a dead battery can be avoided. Keep an eye on your app as it’ll be launching very soon.


Car battery health on your mind since you’re not driving much at the moment? Get a quote for pay-by-mile car insurance here.


The most popular questions we’ve been asked about car batteries:

How often should I replace my car battery?

Typically every 5 years, but there are exceptions. Some batteries have bowed out after as little as two or three years – and some may last closer to 7. It all depends on how regularly the car is driven (or not), and as a result, how well the battery is looked after. 

How do I know if my car battery needs replacing?

Quite simply, if your car won’t start when you turn on the ignition, you may have a flat or dead battery. If you haven’t started the car in a while, you may be able to recharge it, jump start it from another car, or get a breakdown service to start it for you – but if you find it going dead more often, then you may need a new one. If you’ve noticed that the car is struggling to start or you’re seeing any warning signs on the dashboard, it’s worth getting a checkup at the garage to check if there are any underlying problems that are draining your battery before you replace it.

Why won’t my car start?

A flat or faulty battery is the most common reason that cars won’t start. It’s possible that the battery has died, or is dying. You’ll need to find a way to jump start your car, and if that doesn’t work, you may need to consider replacing the battery. Check out some jump start tips here. Keep in mind that not every car should be jump started – you should check your car’s owners manual before doing so. Never try to jump start a car if the battery is cracked or if it’s visibly leaking acid.

How do I know if my battery is getting old?

If your car struggles to start, the battery may need replacing. If you’ve not driven recently, it may be that your battery just needs a jump start and a longer car journey or two to nurse it back to health. If you find it’s going flat more often though, something else may be draining it – or it will need to be replaced. The car should let you know with warning signals on the dashboard, or if it’s been having any electrical issues. Your mechanic will be able to assess and help you with deciding whether it’s time to replace your car battery.

How do I replace my car battery?

You can buy one in any car accessory shop. If you’re not confident in physically replacing it yourself, get a mechanic to help, or some stores will even fit them for you as part of the service. The RAC has a handy step-by-step guide here.

How do I get rid of my old car battery?

Most car accessory shops, repair places or your local waste and recycling centre should accept used batteries to recycle. They can’t just be thrown out with regular household waste, as they’re made of lead dioxide and sulphuric acid, so make sure you dispose of them properly by recycling.

What does the dashboard battery light mean?

It might not necessarily mean that you need a new battery. It could be directing your attention to a problem with the charging system, or an electrical fault. Either way, bring your car to the garage to get to the root of the problem as quickly as possible to prevent any issues from becoming bigger problems.

Can a car battery recharge itself?

Sometimes, yes. When you drive, your car battery is kept recharged, either by an alternator on modern cars, or by a dynamo on earlier cars. So if it’s been flat and you’ve managed to jump start it, driving it will actually recharge the battery. If you’ve been trying to start your car and it’s not working, waiting 20 minutes will let the reaction products diffuse away from the plates and the battery will crank away for a while longer, which might give the impression that it’s recharged itself.

Do I need to charge a new car battery?

A brand new battery should have plenty of charge to run the car. But if you’re going to be storing the battery for a long time before using it in your car, it may be worth getting a trickle charger so it doesn’t lose any charge.

Why is my car battery flat?

It’s undercharged. There could be a number of reasons why this has happened, like accidentally leaving headlights on, doing too many short journeys, an electrical issue in your car that’s draining it, or it could just be an old battery that needs replacing. If it’s nearing the five year mark, look into getting a new one.

What is the voltage of a charged car battery?

Using a voltmeter, you can check the charge of your car battery. If the battery is fully charged, it should be around 12.6 volts with no load. If the reading is below 12.45 volts, it’s a sign that your battery needs to be recharged, or replaced.

How do I get a long car battery life?

Getting into simple habits like balancing out short trips with a few longer ones so the battery stays fully charged and making sure all electrics and lights are switched off before you leave the car will make a huge difference in prolonging your car battery’s life. (Our list of tips detailed above will help you too 😉)

Do I need to water my car battery?

The majority of newer car batteries are considered ‘maintenance-free’, so they’re sealed and designed in such a way that you’ll never have to top them off with water. Save that for your plants!

Can cold weather affect my car battery?

Yes. Extreme temperatures can result in the battery losing its power. Where possible, park your car in a sheltered place like a garage.

Will a flat car battery affect my fuel economy?

Yes. A flat battery means your car’s alternator has to work harder to recover the battery. This puts extra pressure on the engine and uses more fuel. Always keep your battery charged and replace it as soon as possible if it’s going flat.

Does the size of my car battery matter?

Yes. Making sure you have the right battery for your car is vital, otherwise it won’t perform as it should. Always consult an expert if you’re unsure. Guesswork isn’t something you should do when it comes to your car battery.


Disclaimer: Every car battery is different. Without actually examining the car, it can be hard to figure out exactly what’s actually going on with the battery. If you’re having trouble with yours, you’ll get the best advice from a professional. And always get it looked at as soon as possible, so that small problems don’t get the chance to grow into bigger ones. Never drive your car unless you’re certain it’s safe to do so.