The Cold Reality: How Frigid Temperatures Impact Car Batteries

As the cold snap is upon us, car owners throughout the UK should brace themselves for the challenges posed by cold weather conditions. Among the critical vehicle components affected, the car battery takes centre stage. In this technical article, we will delve into the science behind how cold weather affects car batteries. Understanding car owners can take proactive measures to preserve battery health and ensure reliable vehicle performance during harsh winter months.

Chemical Reactions in Cold Temperatures:

Car batteries rely on chemical reactions to produce electrical energy. In colder conditions, these chemical reactions slow down significantly due to the reduced mobility of ions in the battery’s electrolyte. As a result, the batteries ability to accept or deliver sufficient current decreases, resulting in diminished overall performance.

Reduced Cranking Power:

One of the most evident consequences of cold weather on car batteries is reduced cranking power during engine start-up. Cold temperatures cause the battery’s internal resistance to increase, making it more challenging for the battery to supply the necessary power to turn over the engine. This can lead to slow starting, or in severe cases, a no-start situation, leaving the vehicle stranded in freezing conditions. If the ambient temperature is a warm 25°C a fully charged battery has approximately 100% of its power available for engine cranking. When the temperature drops to 9°C a fully charged battery has approximately 66% of its power available to crank the engine. At -20°C a fully charged battery has approximately 40% of its power available to crank the engine.

Energy Drain from Accessories:

During cold weather, drivers tend to rely more on vehicle accessories like heaters, demisters, and heated seats. Running these electrical components places additional strain on the car battery, depleting its charge faster. If the battery is not adequately recharged, it may become unable to power essential systems, resulting in malfunctions or complete failure.

Freezing of Battery Electrolyte:

Prolonged exposure to freezing temperatures can lead to the electrolyte within the battery freezing. The formation of ice can cause the electrolyte to expand, potentially cracking the battery’s internal components. Once the battery is damaged, it will no longer hold a charge and will need replacement. With a battery at 40% state of charge, the electrolyte will freeze at -8°C. With a battery at 100% state of charge the electrolyte will freeze at 33°C.


Cold weather actually slows down the process of sulphation within the battery (chemical reaction slows down with low temperatures) but the increased usage of heaters, lights etc will mean it’s likely that the battery will not be fully charged which could lead to suphation. Sulphate crystals can reduce the battery’s capacity over time and hinder the recharging process. If not addressed promptly, sulphation can lead to permanent damage, necessitating the replacement of the battery.

CTEK’s CS ONE can be the saviour during the winter months. CS ONE has APTO™ Technology which effortlessly identifies your battery type and initiates a tailored charging program without the need for manual intervention. Simply connect the CS ONE to any 12V battery, and let it handle the rest. Forget about buttons, modes, or concerns regarding polarity – our polarity-free clamps eliminate the guesswork, ensuring you’ll never make a wrong connection. Even better, these clamps are spark-free, providing peace of mind even if they accidentally touch. It also adapts to the temperature making it safe to use in any conditions.

Cold weather can be especially harsh on car batteries, affecting their capacity, cranking power, and overall performance. By understanding these effects and implementing preventative measures, car owners can safeguard their batteries and ensure reliable vehicle operation throughout the winter months. Regular maintenance and proactive measures are essential to overcome the challenges posed by frigid temperatures, ensuring a smoother driving experience and peace of mind during the colder seasons.

For more information on the CTEK range of battery charging and support units, click here

Don’t break down on the 5 most haunted roads in UK!

As autumn’s chill envelops the UK, many adventurous souls seek out the thrill of visiting haunted locations, with ghostly tales of mysterious apparitions and eerie occurrences. While these tales add an extra layer of excitement to the journey, one thing no one wants is a vehicle breakdown on the UK’s most haunted roads. Fortunately, the CS FREE is here to save the day, as an adaptive booster that can safely resurrect your vehicle’s battery, ensuring your ghost-hunting expedition goes smoothly.

While the concept of haunted places is subjective and based on folklore and local legends, here are five roads in UK that have reputations for being haunted:

  1. A229 – Blue Bell Hill, Kent:

Known for the ‘Blue Bell Hill Bride,’ this road has a tragic history of accidents. Drivers have reported seeing a woman in a wedding gown, often before encountering unexplained car issues.

  1. A75 – Kinmount Straight, Dumfries and Galloway:

The A75 is dubbed ‘Scotland’s Most Haunted Road.’ Many have reported bizarre experiences here, including phantom hitchhikers.

  1. A30 – Bodmin Moor, Cornwall:

This desolate road is said to be haunted by the ‘Beast of Bodmin.’ While you might not encounter a mythical creature, a vehicle breakdown can be equally distressing.

  1. A38 – Derby Road, Devon:

Drivers on this road have reported apparitions of monks.

  1. A616 – Stockbridge Bypass, Nottinghamshire:

Known as ‘The Flying Scotsman,’ this road has seen its share of paranormal activity.

These stories and legends add to the intrigue and mystery of these roads and locations in UK. Whether you believe in the supernatural or not, exploring these places can be an interesting and spooky experience for those seeking a taste of the paranormal.

With the CS FREE by your side, you can bid farewell to the fright of being stranded in the middle of haunted roads. The CS FREE’s adaptive boost technology offers a safer and gentler boost of your battery, reducing the risk of battery damage or electrical system complications.

When embarking on a journey along the UK’s most haunted roads, the last thing you want is a vehicle breakdown that leaves you stranded in the middle of the night.

With the CS FREE adaptive booster in your toolkit, you can enjoy the thrill of ghost-hunting without the fear of your vehicle’s battery haunting your trip. So, keep your battery charged, your spirits high, and your ghostly encounters memorable!

Find out more about CS FREE and other car battery chargers at

How much does it cost to charge your car battery?

With fuel prices and the general cost of living increasing rapidly, many drivers are looking at ways to save money and make their budgets stretch further.  CTEK, the leading global brand in vehicle charging solutions has revealed that one of the most frequently questions is “how much does it cost to charge my car battery?”

CTEK calculates that, when using a CTEK CS ONE battery charger, and based on a typical electricity cost in the UK of 36 pence per kWh1, it only costs about 19 pence to get an almost flat 12V, 75Ah battery fully charged (assuming battery power efficiency of 85%2 and charger efficiency of 85%).

So that means that you can charge your car battery for an equivalent cost as watching television for 5 hours, or for less than it would cost you to cook dinner in an electric oven for an hour (68 pence), playing on a games console for three hours (30 pence) or running two loads of laundry through a washing machine (61 pence)!3

The precise costs to change your car battery will of course vary, based on how much you’re paying for your electricity and other considerations such as the size of the battery and the overall health of it. The minimal effort needed to maintain your battery on a consistent basis will not only save you the annoyance of a car breakdown, it could also save you money in the longer term.

Regular battery charging can extend your battery’s life by up to three times and, if your car has technology such as a ‘stop/start’ function, this may not kick in if your battery is drained. This will increase the amount of fuel you’re using, and with pump prices still high, fuel is a precious commodity that we really can’t afford to waste.

Even a minor change in the level of charge can affect battery health, decrease its longevity and make a costly replacement battery essential. Battery failure can damage your vehicle’s sensitive electronics, leading to expensive repairs, as well as causing lasting damage to your battery, and if you find yourself stuck on the side of the road with a flat battery, you’ll have the cost and inconvenience of breakdown and recovery to deal with.

Consistent battery charging can actually increase your battery’s life, saving you money on battery replacement. Charging your car battery at least once a month prolongs its life by up to three times, so buying a reliable battery charger, and getting yourself into a regular battery maintenance routine, makes perfect sense.

Beware the dangers of jump starting

If you find yourself with a flat battery, you may be tempted to jump start your car from another vehicle, using jump leads, or from a battery booster pack.

But while this may get you going again, did you know that jump starting can damage your vehicle’s sensitive electronics, leading to expensive repairs, as well as causing lasting damage to your battery?

Today’s modern vehicles have more than 200 mini computers or ECUs (electronic control units) performing a range of tasks from engine management to controlling air conditioning, lights and parking sensors. These computer systems have a sensitive level of around 16 volts, but jump starting the lead acid battery on your car causes a surge of power of up to 20 volts – rather like hitting your car’s electrical system with a lightning bolt – and this sudden spike in voltage can quite easily blow one of these ECUs. And with replacement ECUs costing hundreds of pounds, this is a risk you really don’t want to be taking!

What happens when you jump start a car?

When you jump start a car, the battery booster pack – or, if you are using jump leads, the battery on the connected vehicle – acts as a power reservoir to get the engine started, temporarily bypassing the drained battery. Then, once the engine is running and you disconnect the booster pack or jump leads, the alternator suddenly sees an empty battery and instantly reacts by opening the floodgates to refill it. This massive rise in current creates a spike in voltage, and this is what can cause the damage.

Jump starting a car can damage your battery too, as the alternator is pumping in current at a higher rate than the battery can handle. This causes the battery to heat up, bending the battery plates, leading to the shedding of active material (lead dioxide) and causing a buildup of debris in the bottom of the battery. This damage will reduce the efficiency of your battery and dramatically reduce its lifespan, making earlier replacement necessary.

Safe starting with CS FREE

But you’ll be pleased to hear that there is a safe way to get your car started safely if you find yourself with a flat battery. CTEK’s fully portable CS FREE uses patented adaptive boost technology to get you going again in around 15 minutes.

This is completely safe for your vehicle’s electronics, because the CS FREE gently refills the battery with charge and will let you know when it’s safe to start the car. Then, when the CS FREE is disconnected, the battery is already half full, so the alternator only raises charge slightly, and within safe limits, to top up the battery.

The CS FREE is actually four great products in one portable unit. As well as being an adaptive booster, CS FREE also works as a battery charger, a smart maintainer and high tech power bank. And if you use the CS FREE to maintenance charge your battery on a regular basis, you can actually extend battery life by up to three times.

You can find more information about the CS FREE, which is compatible with all types of 12V lead-acid battery as well as lithium (12V LiFePO4) batteries, here.