Skip to content

How High Heat Affects Your Battery

How high heat affects your vehicle's battery, especially during Summer months

How does high heat affect you?

Being stuck in the middle of the road during a supposed-to-be fun summer road trip is nothing but pure frustration. It happens more often than you’d think, and one of the reasons behind it is a dead car battery. Unlike winter, batteries commonly die due to the heat. In fact, AAA reports that it responded to 2 million battery-related service calls in the summer of 2022 – a record-breaking high. It’s such a concern that AAA themselves have put out articles, addressing it, labelling it as the number one issue in hot weather.

You might be wondering, is the death of my car battery due to the summer heat? In this article, we’ll dive into the possibilities that can happen to your vehicle battery when exposed to high temperatures, while also giving you the best tips in order to avoid this happening and NOT ruin your summer adventures.

What happens to my vehicle’s battery during high heat?


Self-discharge refers to the phenomenon where a battery loses its charge over time, even when not in use. Self-discharge is more common in extreme temperatures. Heat speeds up the chemical reactions within the battery, causing it to discharge faster than it would in cooler weather.

As a result, your battery may be depleted and you may struggle to start the engine, especially if the car has been parked for a lengthy amount of time.

Electrolytes Evaporate

Your vehicle batteries contain electrolyte fluid – a mixture of water and sulfuric acid, which enables the chemical reactions required for power generation. During extreme heat, these electrolytes can evaporate, and as the fluid level drops, your battery's capacity and performance will also be reduced.

Additionally, reduced electrolyte levels further expose the battery's interior components to air, potentially leading to sulfation—a process in which lead sulphate crystals grow on the battery plates.

Corrosion of Battery Terminals

Another possible effect of high temperatures on batteries is the corrosion of their terminals. High heat can speed up the accumulation of rust and corrosion, which affects the battery terminals and connectors.

When the terminals are corroded, it obstructs the energy flow between the battery and the car's components, resulting in lower performance. Worst of all, your car will no longer start at all.

Shorter Lifespan

If your car battery is exposed to high heat, it might also cause irreversible harm to the battery's internal components, demonstrated in part by the negative effects listed above.

Just as extreme heat can cause wear and tear on other parts of your vehicle, it can also accelerate the deterioration of your battery's components. The materials inside the battery expand and contract with temperature fluctuations, which can lead to internal damage and contribute to the breakdown of the battery's structure.

How to Protect Your Vehicle’s Battery During High Heat

According to AAA, car batteries normally last three to five years, ranging from 58 months or more in the most northern regions of the United States to less than 41 months in the most southern regions. However, you can still extend your battery’s lifespan if you take good care of them:

Tip 1: Opt for Garage Parking

When you have the luxury, choose the shelter of a garage for your car. While garages might not be air-conditioned havens, they offer shaded respite from the scorching sun. This protective cover not only shields your vehicle from extreme heat but also safeguards it against potential threats like theft and the wrath of pollen.

Tip 2: Seek Shade When Garage Isn't an Option

When the confines of a garage are unavailable, look for a shady sanctuary. Trees, buildings, and other natural or artificial shade providers can act as your vehicle's shield against the relentless sun. If you do this, the benefits are significant – according to the EPA, shaded surfaces can be a whole 20-45℉ cooler than their sun-exposed counterparts.

Tip 3: Harness the Power of Car Covers

A dash cam continually records video footage while the car is in motion, needing an SD card to store the captured footage. An SD card can keep more footage before it needs to be rewritten, so choosing an SD card with a larger capacity means that the dash cam can save data rapidly and without interruption or delay. Moreover, this also ensures that the dash cam can record high-resolution, high-frame-rate footage without latency.

Tip 4: Investigate Corrosion

The creeping corrosion on your battery terminals is more than just an eyesore – it threatens your battery's performance and lifespan. We recommend you consult your trusted mechanic so they can advise on cleaning or replacing the terminal ends to restore your battery's health, and, if necessary, guide you toward a battery replacement.

Tip 5: Mindful Battery Usage Year-Round

Regardless of the season, do consider your battery usage. Some of us are guilty of leaving lights on, chargers plugged in, or engaging vehicle features like the radio when the engine is off — all of this can strain your battery. The alternator supports these features while the engine is running, but once it's off, the battery shoulders the load.

Tip 6: Radiator Care for Comprehensive Cooling

If you neglect maintenance on your radiator, it can indirectly affect your battery's health. Once the engine overheats due to radiator issues, your battery might also face heightened heat damage. Consistent radiator fluid flushes are recommended for a well-functioning cooling system, as they prevent both battery-related troubles and costly engine failures.

Tip 7: Regular Starting System Check

A failing alternator might not sufficiently recharge your battery during driving, further burdening it. If you begin sensing concerns in your starting system, don’t wait long enough and ask for a professional assessment. It's also a must to have a jump-starter on hand for emergencies.

Tip 8: Stow an Emergency Kit

Packing an emergency kit ensures that if something goes wrong, you aren’t stranded, allowing you to address immediate needs, or properly wait out until help arrives. Useful add-ons such as a flashlight, jump-starter, portable battery, snacks, and drinking water can make for a well-rounded kit.

Another thing to consider during the heat — Your Tires.

Beyond your vehicle’s battery, another part of your car that gets prone to damage during the heat is your trusted tires. As the temperature rises, the air pressure in tires also does.

Scientists discovered that for every 10 degrees (Fahrenheit) increase in temperature, tire pressure rises by one pound per square inch (PSI). It may not sound like much, but passenger vehicle tires typically have only 30-35 PSI.

Therefore, a few pounds of air pressure can go a long way. A tire can pop due to such a large differential – and even if the tire does not blow out, over-inflation can cause early tire wear and impede braking. For better monitoring, we recommend you use a Tire Pencil Gauge with you so you can immediately measure your tire pressure.