Why Do Car Batteries Die?

Why Do Car Batteries Die?

Your car depends on the battery under the hood for everything from running your radio to starting your engine. The battery is the most influential piece of equipment your car needs to drive. When it’s unable to power your vehicle, then your car is unable to start. So what causes a car battery to die?

Our blog explores common reasons a car battery dies, tips for maximum car battery life, and what to lookout for when your battery may be on its way out.

A Few Common Reasons

Car batteries frequently die for a number of reasons. When a battery matures (usually around 3 to 4 years) it can eventually start to wear out and need replacement. While you can’t necessarily stop the metal plates inside your battery from decaying and metal from flaking off (which is the technical reason why these batteries lose their ability to hold a charge and thus “die”), there are some easy ways you can actually drain your battery’s life even sooner.

Leaving Your Lights On
The majority of cars nowadays are pretty good about warning you when you’re about to get out of your car and walk away with the headlights still turned on, but some older models don’t necessarily give you this warning. Your headlights are often an extremely bright and energy-intensive source of light that requires a lot of current to operate—a current which your battery can only sustain for so long. People who leave their lights on overnight often find out the hard way when they go to leave for work the following morning and their car won’t start.

Extreme Weather
Batteries are designed to work in a pretty comfortable temperature range. Too hot and they’ll wear out faster, shortening their lifespan. Too short and the electricity actually can’t pass as easily, which lowers their ability to output the voltage necessary to turn your car’s starter and get the engine going. This is one of a few reasons why cars always seem to be so much more sluggish to start during particularly cold weather.

Corroded Connections
After a while, the metal terminals on the top of your battery (where the battery connects to your car’s electrical system) will oxidize and corrode, which means they’ll wear out and won’t be able to make as clean of a contact as necessary anymore. This means your battery won’t be able to supply as much power and it could even age faster because of the increased resistance between your battery terminal and the electrical lead in your car. However, if you look at your terminals and find that they’re still in good shape, simply tighten them down to make sure the connection is still solid.

Alternator Problems
Finally, your battery is not a continual supply that runs out slowly. It actually discharges while starting your car and then recharges afterward thanks to a device known as your “alternator.” The alternator takes energy your car’s engine produces and turns it into electricity by turning a generator that then feeds back into your battery. When the alternator stops working properly, your battery won’t be able to charge, and you’ll find it dies pretty quickly.

Is My Car Battery Dying?

Unfortunately, modern batteries are made to be extremely strong and provide a lot of turnover power, even when cold, right up until the point where they’re no longer capable. In the past, slow engine turnover would usually signal that your battery was on its last legs. You’d crank the key, your car would turn slower and slower and slower before finally firing and running like normal. This gave you plenty of warning and a chance to go to your local auto parts store to buy a new one before it fully gave out. Today’s modern batteries don’t do that nearly as often, instead providing a much smoother and higher amount of power until the voltage drops too low and they can’t get your starter to crank over at all.

If you suspect your battery may be getting close to its expected lifespan, start listening carefully to your engine as it turns over each morning. If the crank sounds any different or slower than usual, the time may be coming, and if so, it’ll come soon. Second, try to turn your car’s accessory mode on and operate your windows or other high-power feature. If the feature seems to be moving sluggishly, a dead battery may be in your immediate future, so do yourself a favor and get it replaced now.

About Christian Brothers Automotive

At Christian Brothers Automotive, our mission nationwide is to create an uncommonly great experience for customers in need of auto service and repair. Our highly-trained, ASE-certified technicians offer upfront, honest, and practical advice for your car, emphasizing accuracy and realistic solutions for whatever issue you might be having with your vehicle. Each location is locally owned and operated serving communities in Texas, Georgia, Colorado, Minnesota, Kansas, Utah and beyond. Search our interactive map here to find a location nearest you.

Posted by, Christian Brothers Automotive