Many drivers associate dead car batteries with the frosty mornings of winter. While cold weather can certainly test your battery's strength, heat can, and will, damage it. Today, let’s look at the science behind both extremes and how you can help protect that precious power cell under your hood as the warmer temps approach.
First, let’s look at why we associate winter with dead batteries:
Cold Weather Blues
The chemical reaction inside a car battery relies on the movement of ions between the battery's plates. When temperatures drop, this movement slows down significantly. Think of it like honey in the winter - it gets thick and sluggish. This reduced activity within the battery weakens its ability to deliver its full burst of power, making it harder to crank the engine.
Adding to the challenge is the increased resistance from the engine itself. Motor oil thickens in cold weather, making it harder for the engine's internal components to move freely. This extra resistance requires more power from the battery to overcome, putting additional strain on its already reduced capacity. It’s no surprise then, with these extra obstacles, even batteries with life left in them get traded out during the winter months.
But Here's the Shocker
Despite the above, extreme heat poses a greater threat to your battery's long-term health. Under the hood, temperatures can soar well above 140 degrees Fahrenheit. This intense heat accelerates the rate of chemical reactions within the battery, leading to:
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Electrolyte Breakdown: During normal operation, the battery's electrolyte (a mixture of water and sulfuric acid) breaks down slightly into hydrogen and oxygen gasses.
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Evaporation: The battery's electrolytes, a vital liquid solution, can evaporate at a quicker pace. This reduces the battery's ability to hold a charge and can eventually damage its internal components. Unfortunately, a nice, cool Gatorade won't help us here.
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Corrosion: High heat can exacerbate corrosion on the battery's lead plates, further weakening its performance and lifespan.
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Warped Plates: The intense heat can cause the battery's internal lead plates to warp or buckle. This reduces their surface area, hindering the efficiency of the chemical reactions that generate power.
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Degradation of Active Material: The high temperatures can accelerate the breakdown of the active materials on the battery plates, further reducing its capacity to hold a charge.
Of the list, “evaporation” can create the most confusion, as how do “closed” batteries allow such a thing to happen? Well, car batteries are not truly sealed units. They typically have a vent plug that allows the release of gas buildup during normal operation. Though it helps avoid explosions, which is nice, this vent also allows some water vapor to escape. It's important to note that most modern batteries are designed to minimize water loss. They use a mixture of water and sulfuric acid that reduces evaporation and may also have features like labyrinths that condense water vapor and return it to the electrolyte. Alright, enough of that, how do we…
Protect Your Battery from the Heat:
Here are some ways to keep your battery cool and help it help you longer:
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Park in the shade whenever possible: Your engine does enough heat generation of its own, but don’t forget the nuclear fusion ball in the sky beaming energy right onto the hood.
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Keep your battery clean and free of corrosion: If you don’t already have one, a battery terminal kit is cheap, and a bit of battery grease can keep the corrosion at bay.
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Ensure proper ventilation around the battery: Remove any leaves or debris that might be blocking airflow.
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Consider a battery heat shield: Most modern vehicles have this in place already, but it doesn’t hurt to make sure it’s there. Hot-rodders and modders might remove it for aesthetics or extra space, while it’s also possible it got torn and disposed of without a replacement.
Know When to Replace Your Battery
It can vary due to a variety of factors, but most car batteries have a lifespan of 3-5 years. If your battery is nearing the end of its life, even moderate heat can cause it to fail. Here at Greensboro Auto Center, we offer complimentary battery testing to help you identify any potential issues before they leave you stranded.
By following these tips and taking advantage of our free battery testing service, you can ensure your car starts smoothly all year round, no matter the season. Drive safe out there!