Why Do Car Batteries Die in Cold Weather?

Climates can kill your battery, learn the ways to take care of.

One of my greatest frustration is when my car battery dies in cold weather. It is no joke climbing into a car under freezing temperature only to find out it won’t start. Almost always, the culprit is a dead battery. Read on and I’ll tell you the reasons why batteries die in winter.

Why do car batteries die in cold weather? Car batteries die in winter because they lose almost 32% of their charge at 32°F. and 60% of their capacity at 0°F.

Contributing factors that cause a battery to die in cold weather are age and a greater amount of draw from the car’s electrical accessories as well as from the starter motor,

Why Batteries Die In Winter

Batteries do not last forever. Like everything else in this material world, batteries also have a life expectancy. Unfortunately, some batteries die even before they reach their life’s duration. Most frequently, they meet an untimely death during winter time.

Starting an engine requires a lot of power. Under normal condition, your battery is up to the demand since it is built to do exactly that – deliver a burst of strong power at a short period of time. But, in winter, an engine needs twice as much amperage to get going. When the battery’s capacity drops considerably because of the cold, then you are confronted with a car that won’t start.

Battery capacity is diminished during the cold season because the motor oil thickens and the engine becomes difficult to crank causing the starter to draw more power. This is especially true when the engine oil that you’re using is a single grade motor oil and not one with multi-viscosity weight applicable to different temperatures.

Driving during the cold season also makes your battery work harder. Electronic accessories such as the windshield wiper, heater, headlights among others, that are powered by your car battery are put to used more often. This is because it gets dark earlier than usual and most of the time the weather is bad.

Since the capacity of your battery is already diminished by the cold, this added strain can precipitate the death of your battery, especially when it is already a bit old.

Another cause of an untimely death of a battery during the cold season is its very nature. Most batteries used for motor vehicles are lead acid batteries. These type of batteries experience a phenomenon called self-discharge that reduces the capacity of the battery naturally. Extreme temperature increases the self-discharge rate of a battery.

In summer, the heat causes the water in the battery’s electrolyte to dry up. This brings about an accumulation of sulfation which slows down the process of conversion from chemical to electrical inside the battery. When winter comes, the cold temperature further slows down the conversion process and diminishes the battery’s capacity to function.

How To Keep Battery From Dying In Cold Weather

There are ways to avoid having your battery die on you during the cold weather. Here they are:

● Have your battery tested

If you have an old battery, meaning three years old or more, before the onset of the cold season, have it tested. Also, have the electrical system of your car checked. You can have the tests done by your mechanic when you bring your car for a routine tune-up or oil change.

● Inspect and clean the terminals and cables

Over time there will be a buildup of sulfation and corrosion on the terminals of your battery. It is important that you do a regular inspection of your battery to check for such build up. This gunk a poor conductor of electricity, will slow down cranking, prevent your battery from holding a full charge, and eventually cause its death.

Apply a mixture of water and baking soda on the terminals and remove the buildup with a stiff wire brush.

Make sure that the terminals and cables are tightly in place.

Other things to inspect are the cables, nuts, and fasteners. Make sure that they are clean and in good condition.

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● Keep your battery fully charged

A weak battery will freeze even at 32°F, but a fully charged battery can withstand a low temperature of up to -76°F.

● Unplug electronic devices and accessories

When you switch off the ignition of your car, see to it that electronic devices such as chargers, tablets, and mobile phones are unplugged. Your battery’s capacity will dwindle over time from the aggregate effect of several devices draining its charge when the engine is not running.

● Drive your car

Driving charges your battery. Give your car a daily spin of about 20 to 30 minutes to charge your battery. If your car is left sitting idle for weeks or even days, there is a good chance that when you need it, it won’t start.

● Get a new battery

If your battery is three years old or older and you’ve observed some of the symptoms of a dying battery listed above, you better buy a new one and replace your old battery before the cold sets in.

Batteries Also Die In Summer

Winter time is not the only time car batteries die. Even in the summer, batteries also have a hard time. The hot temperature during summer time also has an adverse effect on your battery. Actually, heat could shorten your battery’s life faster.

A battery continually exposed to a 92°F temperature has a 50% chance of dying sooner than one that is operated regularly at a comfortable 77°F temperature. As per records of the International Battery Company, the life of a battery is shortened by 50% for every 15° increase over the 77°F normal operating temperature.

In fact, intense heat could be far more harmful to a battery than extreme cold. The Car Care Council considers overcharging and heat as the two main threats to a battery’s longevity. The electrolyte evaporates when heated, and when you fail to top it off, the damage to your battery could be irreversible. In a like manner, overcharging damages the battery internally and can substantially shorten its life. It could even cause the battery to blow up.

The Inner Workings Of A Battery Explained

To understand why car batteries are highly susceptible to extreme temperature, you must first be familiar with the inner workings of a battery.

The most common batteries used for cars, vans or trucks are lead acid batteries because they are not only dependable, they are also fairly cheap.

Lead acid batteries consist of lead plates submerged in an electrolyte solution which is a mixture of sulphuric acid and water, housed in a plastic casing. A pair of lead plates is called a cell which, when fully charged, generates 2.1 volts of electricity. A 12-volt battery, therefore, is made up of six cells.

On its own, a lead acid battery doesn’t generate a charge. It receives a charge from an external power source that produces a chemical reaction between the electrolyte and the lead plates. As the chemical reaction takes place, the negative and positive lead plates are gradually being layered with lead sulfate in a process called sulfation.

Sulfation is a battery’s bane. It lessens the ability of the battery to hold a complete charge. Self-discharge makes matters more complicated. This is a natural characteristic of a battery whereby, over time, it loses charge even without the chemical reaction. If you don’t charge your battery for a long period of time, it can be fully discharged, and damaged beyond recovery.

Car batteries operate on an electrochemical process, thus they have built-in limitations that are affected by numerous variables which have an effect on their performance. Climate is one such variable. The life of your battery will depend on the weather condition of the area where you live.

The lifespan of your battery is also affected by the number of electronic accessories you have in your car and the length of time they are used.

The frequency and distance of your trips are also factors that affect your battery’s longevity.

The normal lifespan of a lead acid battery is from three to five years. But, your battery could die an untimely death because of the variables mentioned above or it can live way beyond its life expectancy. This will all depend on how you take care of your battery. Regular testing, inspection, and cleaning of the battery terminals could help maximize the life of your battery.

Symptoms Of A Dying Battery

Batteries don’t just fall dead without warning. Usually, there are signs that your battery is not well. Watch out for these signs:

The battery warning light on the dashboard is on
● Slow cranking of the engine
● The dim of your headlight is yellow instead of white
● Some electronic accessories are not functioning
● The dome light is dim
● A hoarse car horn
● A grinding or clicking sound when the ignition is switched on
● The smell of a rotten egg or sulfur
● A cracked or swollen battery case
● Your battery is three years old.


Your car battery will die in cold weather or even in hot weather because, by its very nature, batteries are vulnerable to extreme temperature. In winter, the battery’s capacity drops because of the cold. In summer, the heat causes the sulfuric acid to evaporate, and when it is not top off it could cause damage to the battery that will shorten its life. To avoid a mishap, follow the suggestions listed above to prevent your battery from dying.