How Long Does It Take To Charge A Car Battery

Car batteries can become flat for a whole range of reasons that include leaving the lights on to general wear and tear. Luckily they can be easily charged but how long does a car battery actually take to become fully charged and ready for use?

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How Long To Charge A Car Battery
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There is nothing worse than coming out to your car and finding out that it won’t start because of a flat battery. Although you may be able to jump start the car to get up and running again, it isn’t always recommended. Jump starts are best used as a worst case scenario to get your car running and you should always try and fully charge the battery if possible.

However, the time it takes to charge a car battery isn’t always suitable for most people that need to get somewhere. Even if you owned the best rated car battery charger, it still may take a few hours to fully charge the car’s battery.

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How Long Does It Take To Charge A Car Battery

The time it takes to charge a battery can be anywhere from 4 to 24 hours. Certain factors such as the amperage of the charger, battery size and whether the battery is completely dead will play a role in how long it will take.

If you only want to get the car’s battery back to a usable level, it may only take 2 to 4 hours. Once it’s back to a usable level, it can then be charged normally by the alternator as you drive the car.

It’s worth pointing out that if you opt for a higher amperage charger (i.e. the CTEK brand offer a 10A charger), the time it takes to charge a battery is going to be far less. There really is no definitive time it takes to charge a battery due to the fact there is such a variety of batteries, chargers and external factors to consider.

How To Prevent A Car’s Battery Going Flat

Use a Trickle Charger

Whether your car only comes out when the suns out (very rarely for us in the UK!) or it’s a classic, the best way to keep the battery safely topped up is to use a trickle charger. It’s designed to be left on the car for long periods and works by safely topping up the battery at the same rate as its self-discharge.

Avoid Using Electronics Without The Car Running

An easily preventable cause of a battery going flat is to avoid using certain components without the car running. This can include anything from listening to the car’s radio to moving electrically adjusted seats.

Drive The Car More Often

Unless your car has a faulty alternator, as you drive your car, it will be charged by the alternator. Therefore, driving the car more will keep the battery topped up and ready for the next startup.

Locate Any Parasitic Battery Drain

One of the most frustrating reasons a battery loses its charge can be due to a parasitic battery drain. It’s frustrating due to the fact that it can be very difficult to locate and take hours of testing. Some common causes include hidden GPS trackers, malfunctioning car audio components, dome light and so much more.

Battery Keeps Going Flat

If you have tried all of the above methods to prevent the battery becoming flat with no avail, it may be time for a replacement battery. The car’s battery isn’t a component that lasts forever and rather than guessing how long it will take each time to charge each time, it’s probably best just to replace it.


The time it takes to charge a car battery will vary from battery to battery and whether it’s completely dead. Avoiding a battery becoming flat is fairly straightforward but if it can’t be prevented, it’s advised that you simply buy a new battery.

The CTEK brand are at the forefront of battery charging technology and we (as well as thousands of professional mechanics and car enthusiasts) highly recommended their charging devices. If you want to reduce the time it takes to charge a battery, we recommend that you purchase one of their more powerful chargers.

The Author Who Worked On This Article

author dan darimo

Dan Morgan

As a keen DIY’er, gardener and somebody that loves the latest tech, Dan is someone that brings years of experience in multiple trades. Since buying his first house, he has been obsessed with renovating properties and filling it with the latest products. This has led him down the road of testing hundreds of products and creating in-depth “how-to” and informative guides that offer his first-hand experience. Other interests include working on cars, keeping fit through sports or his home gym, caravanning and drinking great coffee.

If you would like to read more about Darimo and the authors, you can visit our about page. This goes into great detail regarding how we test products, create our guides and everything else.

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