How to Protect Your Car Battery This Winter

Article summary

• Understand the impact of cold: Freezing temperatures significantly reduce your car battery's efficiency by slowing down chemical reactions, making it harder for your engine to start. At 32°F, a battery loses about 30% of its strength.

• Recognize warning signs: Look out for signs of a failing battery, such as a slow-to-start engine, dimming headlights, a clicking sound when turning the key, or an illuminated battery light on your dashboard.

• Take proactive steps: You can protect your battery by parking in a garage, limiting short trips, keeping terminals clean and using a battery warmer. For electric vehicle (EV) owners, preconditioning the battery while plugged in is key.

• Know your support options: Ignoring the signs can lead to costly tows or on-the-spot battery replacements. Your AAA Membership offers peace of mind with services like battery testing and replacement and emergency roadside assistance.

The sun is setting earlier; the last leaves are clinging desperately to the barren crowns of the trees, and temperatures are dipping a little more each day—clear signs that winter is on its way. If you’re a vehicle owner living in states susceptible to harsh winters, a proactive approach to car care is imperative, especially for your car battery maintenance.

Cold weather drains battery capacity, makes engines harder to start and increases the risk of unexpected breakdowns. Preparing now can help you avoid stress later. If you’re ready to winter-proof your vehicle, but don’t know where to start, AAA can help. 

How cold weather impacts your car battery: The science explained

Did you know that when temperatures drop to freezing (32 degrees Fahrenheit), your car requires 30% more energy to start? This percentage increases to 50% at zero degrees. The drop in functionality is a result of the cold’s effect on various chemical reactions inside the battery. Affected chemical reactions include:

• Reduced electrochemical reaction – The chemical reactions that produce electrical energy slow down, leading to decreased battery output and voltage.
• Reduced lead sulfate solvation – Lower temperatures hinder the dissolution of lead sulfate crystals during charging, leading to poor charging or total capacity loss.
• Reduced lithium-ion battery performance – Cold weather can significantly reduce the capacity and discharge rate of lithium-ion batteries. They can lose up to 20% of their capacity.
• Increased internal resistance – The electrolyte solution in your battery thickens as temperatures drop, which causes it to oppose the flow of electric current. The higher the resistance, the harder it is for your battery to deliver power efficiently.
• Increased risk of sulfation – Sulfation is the formation of lead sulfate crystals on the battery plates when the battery is in a discharge state. This is an irreversible process that can permanently damage a battery’s capacity.

To put it simply, your battery must work harder to do less work. If not properly cared for, it could permanently lose capacity, which ultimately reduces the lifespan of your battery.

Warning signs your car battery is failing

If your car battery is failing you, there will be warning signs. Knowing what to look out for could help you save your battery. Key signs include:

• Slow engine cranking – Engine turns over sluggishly or takes longer to start.
• Dim or flickering headlights – If your lights dim while idling or brighten during acceleration, it could mean the battery isn’t supplying steady power.
• Clicking sound when starting – Rapid clicking when trying to start your vehicle typically means there’s not enough power to engage the starter.
• Battery indicator light – If illuminated, the vehicle warning light could mean there is low voltage coming from the battery or charging system.
• Electrical issues – Power windows moving slowly, interior lights dim, radio or other systems reset sporadically.
• Sulfur smell – A rotten egg smell coupled with corrosion and a swollen battery case could be indicators of internal battery damage.

To catch these issues before they become a permanent problem, consider a seasonal battery check before winter takes over.

What happens if you ignore battery issues?

If you’re not proactive or if you ignore the warning signs, you could find yourself stranded, dealing with expenses you didn’t have in your budget. Sure, you may be able to jump your battery to get where you need to go, but your jumper cables are only going to be helpful if someone else is around.

If there’s no one around, you’re likely going to be calling for help. Below are some of the costs you may run into:

• Mobile battery installation – If a professional cannot jumpstart your battery, they may offer to replace it on the spot for you, but this won’t be free. Even with an exclusive membership discount or roadside assistance coverage, a new standard replacement battery could cost you from $90-$200, depending on the brand.
• Tow – If a jump fails you, a mobile battery replacement is not possible, and you don’t have roadside assistance, you may be paying for a tow. This cost typically ranges from $2.50 to $7.00 per mile, averaging approximately $109. Time of day, distance and vehicle size will influence the final total.

Battery tips for electric vehicle owners

Electric vehicles (EVs) are a game-changer, but their batteries are especially sensitive to cold weather. Here’s how to keep your EV running smoothly this winter:

• Precondition your battery – Most EVs allow you to warm up the battery while it’s still plugged in. This helps maintain range and performance without draining the charge.
• Use a Level 2 charger – Faster charging can help keep your battery warm and ready to go.
• Plan for reduced range – Cold weather can reduce your EV’s range by up to 40%. Plan your trips accordingly and keep an eye on your charge level.
• Park indoors when possible – A garage or covered parking can shield your EV from extreme cold, helping to preserve battery life.
• Limit use of cabin heating – Heating the cabin uses a lot of energy. Instead, rely on heated seats and steering wheels if your EV has them—they’re more efficient.

Common myths about winter battery care

When it comes to winter car care, misinformation can lead to costly mistakes. Let’s bust a few common myths:

• Myth: Idling your car warms the battery – While idling warms the engine, it does little for the battery. Instead, take a short drive to let the alternator charge the battery.
• Myth: Batteries don’t need maintenance – Even maintenance-free batteries benefit from regular checks. Cleaning corrosion and testing voltage can extend their life.
• Myth: A fully charged battery won’t freeze – Extreme cold can still damage a fully charged battery, especially if it’s old or weak.
• Myth: Jump-starting is always the solution – Jump-starting can get you moving, but it’s a temporary fix. If your battery is struggling, it’s time for a replacement.

Winter battery care tips to keep your car running

Ensuring your battery survives the cold requires intentionality. These preventative measures could give your battery the umph needed to make it through the winter. Here’s what you can do to get more mileage out of your battery this winter:

• Park in a garage or shelter – While it won’t stop the cold completely, even a few degrees of warmth can make a huge difference in the life of your battery.
• Use a battery warmer – These devices help to regulate your battery temperature and prevent the extreme cold that could cause damage.
• Clear corrosion from terminals – Corrosion reduces conductivity. By keeping your terminals clean, you’ll improve your battery’s performance.
• Limit short trips – Your alternator requires time to charge your battery. Short trips prevent a full charge. Consider slightly longer drives to give your battery time to charge.

Why AAA is your winter car care ally

If you’re a AAA Member, you can take advantage of a variety of services and discounts that can both help you prepare for winter and bail you out if your battery fails you. Here’s how:

• Battery testing and replacement services – Know what’s going on with your battery before it’s too late.
• Exclusive member discounts – For inclement weather issues, AAA membership provides a variety of services and discounts that may include towing options, battery warranties, and 24/7 mobile service.
• Emergency roadside assistance – AAA is available anytime, night or day. Whether you’re looking to get a read on your battery’s health or needing roadside support, AAA has you covered.

Don’t wait for the first signs of cold weather to hit to check your battery. By taking a proactive approach, you can save yourself time and money while avoiding the frustration of an unexpected breakdown. For peace of mind and exclusive deals, sign up for AAA today if you’re not already a member.