Cold Weather + Your Car Battery: How the Chill Takes a Toll

It’s a well-known fact that cold weather conditions affect battery performance.
At freezing temperature, your vehicle’s battery can lose cranking amperage, and without proper maintenance, you could find yourself stranded with a dead battery.

Not a pretty picture, right?

However, cold weather car battery performance isn’t just a battery problem.
There’s a human element that contributes to it, too.

We’re going to dig a little deeper to understand how frigid temperatures impact battery life, and how you (as the driver) could indirectly factor in. We’ll also explore ways to sidestep potential winter weather battery woes.

This Article Contains:

How Cold Weather Affects Your Car Battery
Cold Weather Car Battery Care: 9 Winter Survival Tips
How to Choose the Best Car Battery for Winter Months
3 FAQs About Car Batteries

Let’s get started.

How Cold Weather Affects Your Car Battery

Cold temperatures and battery performance have a direct correlation.
If you have a gasoline or diesel engine vehicle, you’re probably using a lead-acid battery. Here’s how the cold affects your battery:

1. Diminishes Battery Capacity

In a lead-acid battery, chemical reactions generate the electricity that activates the starter motor. However, frigid temperatures thicken the battery fluid (electrolyte), making it more viscous and slowing this reaction rate.

As a result, at 32°F (0°C), the battery loses about 30% of its cranking amperage, and at 0°F (-18°C), this number can drop to around 60% compared to normal. That’s why a battery’s cold cranking amps (CCA) is important, as it signifies a battery’s ability to crank an engine in low-temperature conditions.

2. Slows Battery Recharge Rate

Because a battery’s chemical reactions are slowed in the cold, its recharge rate also drops. This means your alternator will take longer to recharge your battery fully.

3. Increases Battery Load

The cold thickens not only battery fluid but also engine oil, making your battery work harder to start your car. On top of that, using heating, headlights, windshield wipers, and car chargers adds to the battery load, increasing the chances of battery failure, especially if it’s an older battery.

4. Freezes Battery Fluid

When the temperature drops below -40°F, battery fluid can freeze and expand, putting pressure on its lead plates and casing. The expansion can cause your vehicle’s battery to crack or rupture, resulting in acid leaks.

If your battery isn’t fully charged, battery freeze can happen even in milder, above-freezing temperature. For instance, a battery at 80% charge could potentially freeze at -20°F.

5. Causes Moisture Build-Up

In cold weather conditions, moisture builds up inside the battery, leading to corrosion on the battery’s lead plates. Water dilutes the battery electrolyte; in rare cases, the water can cause a short circuit.

It’s worth noting that electric vehicle batteries aren’t immune to the cold either.
Lithium-ion batteries are prone to lithium plating (formation of metallic lithium) in extremely cold conditions. Lithium plating occurs when lithium ions build up in the battery’s anode.

Luckily, even when dealing with extreme temperature conditions, you have options to prevent battery failure. Let’s explore them.

Cold Weather Car Battery Care: 9 Winter Survival Tips

Here are some tips to help prevent a battery problem or, worse, a dead battery in winter:

1. Take Longer Drives

Short trips will only recharge the battery partially. In contrast, an occasional 30-minute drive gives your battery enough time to recharge and boosts overall battery life.

2. Minimize Electrical Load

Minimize using heated seats, high-powered audio systems, or interior lighting when the engine is off. This helps the battery cope with the increased demand for starting power in cold temperatures.

3. Protect Your Car from Extreme Cold

Park your petrol or electric vehicle in a heated garage or a covered area. This will provide some insulation against the extreme cold and keep your battery warmer.

4. Power Down Your Car Properly

The cold affects not only your battery but you, too.

When you shut down your car, make sure to turn off the headlights. Close doors properly to prevent a parasitic drain from interior lighting before you rush off to warmer shelter. The last thing you need is to return to a dead car battery.

5. Clean the Battery Terminals Regularly

Use a baking soda and water solution and gently scrub the battery terminals with a toothbrush to prevent corrosion and improve the battery’s lifespan. Wear gloves and safety goggles to avoid chemical exposure.

6. Test Your Car Battery

Extreme temperatures can cause havoc on your car battery, whether it’s the chill of a frigid winter or scorching hot weather. Internal corrosion from the high temperatures of summer can weaken your battery, too. So, test your battery to make sure it’s ready for when the mercury drops.

7. Use Low-Viscosity Engine Oil

Low-viscosity engine oil gets to the essential parts quickly, helping you start your car faster in the cold.

8. Invest in Cold-Weather Engine Accessories

Accessories like an engine block heater or battery blanket can help maintain a warmer temperature around your battery. This makes it easier to start your vehicle in low-temperature conditions.

9. Use a Battery Charger

Use a trickle battery charger or a conditioner to provide a low, constant charge when your car is in storage for some time. This helps maintain a fully charged battery, which is less likely to freeze than one with low power. It also helps improve battery life.

These car battery tips can help keep your battery healthy, but remember, selecting the right cold-weather car battery is key to winning half the battle.

How to Choose the Best Car Battery for Winter Months

Consider these factors when selecting a car battery for winter weather:

Choose the appropriate battery type for your vehicle, such as standard flooded batteries or AGM batteries. AGM batteries perform better than flooded batteries in low temperatures. While some limitations exist, upgrading from a flooded battery to an AGM battery is possible.

Note: AGM batteries with a cold cranking amps rating of 1000 perform better than a lead-acid battery in extreme temperatures. They offer a low self-discharge rate, excellent vibration resistance, and don’t expand like a flooded battery when frozen.

Ensure the battery group size aligns with your car’s physical dimensions, terminal locations, and type requirements.

Pick a battery with a higher CCA for dependable starting power.

Refer to the manufacturer’s website for reserve capacity information — how long the battery can run before dropping to 10.5V.

Examine vibration resistance ratings on labels or product descriptions. Higher ratings suggest better suitability for cold temperatures.

Need more details on car batteries?
We’ve got you covered.

3 FAQs About Car Batteries

Here are three commonly asked questions regarding car batteries and their answers:

1. How Do Car Batteries Work?

Car batteries store chemical energy that’s converted to electrical energy to start your engine.

When you turn the ignition, your battery releases stored energy, initiating a chemical reaction between the battery’s lead plates and an electrolyte solution of sulfuric acid and water. This chemical process produces electrical power that flows to the starter motor, cranking the engine.

While the engine runs, the alternator recharges the battery and supplies power to most of the car’s electrical systems.

2. How to Safely Warm Up a Frozen Car Battery?

Follow these steps to warm up a frozen car battery safely:

First, inspect the battery for visible cracks or leaks.

If there are no cracks, place the frozen battery in a warm area to thaw slowly.

Next, use a portable heater or indirect heat source to raise the battery’s temperature to at least 40°F. Allow the battery to warm up for approximately 30 minutes.

Try jump-starting the vehicle. Ensure secure and correct connections for the jumper cables.

Let the vehicle run if it starts so the alternator can recharge the battery. If the car doesn’t start, consult a professional mechanic.

3. How to Test a Car Battery?

You can test a car battery with or without a multimeter, but a multimeter provides a more accurate assessment. Here’s how to do both:

A. With a Multimeter:

Turn on the multimeter and set it to DC voltage.

Connect the positive probe (red) to the battery’s positive terminal and the negative probe (black) to the negative terminal.

A fully charged battery typically reads around 12.6 volts or slightly higher.

If the voltage is significantly lower, it can point to a battery problem.

B. Without a Multimeter:

Turn on the headlights. If the headlights appear dim, you could have a weak or dying battery.

Try starting the engine. If it cranks slowly or struggles to start, you may need a battery replacement.

Stay Ahead of Cold Weather Car Battery Woes

Cold weather can lower battery performance by reducing capacity and recharge rate. Increased battery load, an undercharged battery, or corrosion could also leave you with a dead car battery. However, you can counteract these effects by following our car battery tips.

If you need professional help with a battery replacement, why not rely on AutoNation Mobile Service?
We provide on-demand auto repair services right from your driveway.