How High Temperatures Impact Your Car Battery

The battery in your vehicle was designed to withstand the elements and keep you from getting stranded. But when temperatures inch close to or hover in the triple-digits, even the most rugged battery can take a beating. Extreme heat can drain a battery and reduce its overall life, making it hard to start your vehicle in the fall and winter. We have some tips to help protect your battery from the heat and maintain it for years of use.

Understanding Car Batteries

Whether you drive a gas-powered car or an EV, your vehicle has a standard 12-volt battery that starts the engine or engages the batteries and startup sequence. These plastic box-like necessities are hard to miss. However, that simple-looking battery hides some impressive age-old inventiveness.

Today’s lead-acid battery technology that turns chemical energy into electricity has been around since the U.S. Civil War. While modern batteries are built better than their century-old counterparts, the idea remains the same. To start a gas-powered vehicle or get an electric vehicle moving, your standard battery needs enough power to get things working. That includes the motor, electronics, comfort controls, and more.

So, how does a car battery work? Essentially, the battery in your vehicle likely contains rows of cells inside a plastic casing (the box you see). Each of those cells has a lead dioxide plate along with a lead plate submerged in sulfuric acid. Thanks to the creation of lead sulfate and ions, hydrogen and lead sulfate are produced to create two volts of electricity. Most car batteries have six of those cells, adding up to 12 volts of energy. That energy is then moved out to the positive or negative terminals and then delivered to your vehicle. Once the vehicle is started, the alternator feeds energy back to the battery. The chemical reaction then happens in reverse, helping recharge the battery.

Check out our article about how batteries work.

The Impact Of Heat On Car Batteries

Sure, the life of your car battery depends on where you live, how much you drive, and how often you start your vehicle. While it might seem like it’s the cold that kills batteries, since winter is when most batteries meet their demise, it’s actually the summer heat that does the most damage. That’s usually the case whether you drive a gas-powered truck or an electric vehicle.

Because of excessive heat, the water in your battery can evaporate. This can lead to damage and a loss of power. Additionally, heat can promote battery swelling as well as corrosion on the posts that deteriorate the internal structure.

But it’s not just the heat that can damage your battery.

Cold Weather

When the cold weather hits, a tired battery will show its wear and tear. Additionally, those colder temperatures will finish off a struggling battery.

Changing a car battery


Is your battery strapped down or bolted in place? Allowing your battery to rattle around can cause damage. Plus, if both terminals ever make contact with any metal on your car, it could cause a fire.

Under or Over Charging

If the winter weather is draining your battery down, use a trickle charger to keep it at or near a peak charge. But be careful. Under or over-charging a battery can damage it and reduce its life.

Checking a car battery


A well-maintained battery is a happy battery that won’t leave you stranded. Stop by Les Schwab for a free visual inspection of your battery.

Can My Car Batteries Lifespan Be Affected By Where I Live?

Yes, if you drive in a region that experiences extreme heat waves or regularly faces harsh winters, your car’s battery may be impacted. Thankfully, there are ways to protect your car battery and get the most out of your 12-volt investment.

How To Prolong the Life of Your Battery

A handful of tips can improve the life of your battery, even in extreme heat conditions.

Take regular trips to the store (or elsewhere)

Drive for at least 20 minutes every couple of days to ensure your battery stays charged. If you don’t plan to drive for a week or more, use a trickle charger to keep your battery charged.

Park in the garage or shade

Do you have access to a garage or shade? Parking in those spots can really reduce the daytime heat of your vehicle.

Turn off the music

Don’t run the radio or other electronics with the car turned off. This can harm the battery even in moderate temperatures.

Look for post-corrosion

If you see any, clean it off with an old toothbrush and a mixture of baking soda in a bit of water.

Choosing The Right Battery for Hot Climates

When comparing batteries for a hot climate, look for ones with a higher electrolyte-to-lead ratio in addition to a higher reserve capacity (RC) rather than cold-cranking amps (CCA). The CCA is an important feature in any battery, but the higher the RC the more excessive heat it can withstand. Look for a battery that can reach at least 25 amps before dropping voltage.

When your vehicle needs a new battery, Les Schwab is here to help with batteries for everything you drive, including today’s EVs.

Technician talking with a customer

Car Battery Testing and Replacement At Les Schwab

If your battery faces harsh summertime heat and/or frigid cold winters, a quick and free visual inspection at Les Schwab can help you avoid getting stranded. We can even test your battery and charge it overnight if it’s just a little low. Need a new battery? Our team of pros will use the latest battery installation techniques and technology to keep the power flowing to your vehicle.

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