How Long do Batteries Last

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Answering Your Questions
People often ask, "Where do you come up with the ideas for articles in the Lithia Research Center?" Often, the questions that spur an article come from questions posed by our valued customers. We were recently asked how long a car battery lasts. The answer is both simple and complex.

Things to Know about Car Batteries

Most conventional gas cars use lead acid batteries to provide the electricity to start the vehicle and provide power for electrical components. If the battery dies, the car won't start. Inside lead acid batteries, there are lead dioxide plates (PbO2) and Lead (Pb) plates. These haven't changed much since the 1880's, though energy density, overall battery life and dependability has improved greatly over the years.

All lead acid batteries consist of flat lead plates that are immersed in an electrolyte of water and sulfuric acid. The average 12-volt battery consists of a series of cells that each produce 2.1 volts. Thus, a 12-volt battery includes six single cells inside a protective plastic case for a total of 12.6 volts.
Lead acid batteries do not generate voltage on their own, rather they store the charge from another source.  When a battery is charged it produces ions that move back and forth between the plates to generate electricity. One of the disadvantages of this kind of system is that the battery is filled with caustic acid that can leak out of the plastic casing if the battery is tipped over or cracked. Absorbent Glass Mat (AGM) sealed batteries solve this problem by using glass mat separators within the cells to absorb the acid and keep it from sloshing.
Picking out a Replacement Battery
Many times, a battery that has discharged and won't start can be recharged through jump-starting the car or using a battery tender to charge the battery back up to a full charge. But when a battery gets old and can no longer hold a charge, it is time to replace it. Here are some terms you should know.

Battery Group - also known as the Battery Council International (BCI) group, determines the size, voltage, and terminal locations of the battery. When looking for a new car battery you'll want to match the battery group that fits your specific year, make and model of vehicle. You'll find specifications for the proper battery for your car in the Owner's Manual. 
Cold Cranking Amps (CCA) tells you how well a battery works in extreme cold. The higher the CCA number, the more powerful the starting power. For optimal cold-weather performance, you'll want a battery that produces at least 600 cold cranking amps.

Reserve Capacity (RC) tells you how long a battery can power your vehicle without help from the charging system. RC represents the amount of time, in minutes, that a 12-volt car battery can run without dipping below 10.5-volts. The larger the reserve capacity, the longer the battery can provide power. For instance, the average 12-volt lead battery should have an RC of 170 to 190 minutes while a 12-volt lithium-ion battery should have an RC of 240 minutes.

Battery Life

The average 12-volt lead acid car battery should last from three to five years but there are things you can do to extend your battery life. Keep in mind that the battery you buy may be older than you think. You'll find the manufacturing date of the battery on a sticker affixed to the top or side of the battery case. If the battery was already a year old when you bought it, you have reduced the life of the unit before it ever starts your car. Other things such as only driving for short trips, living in harsh climates such as extreme cold or excessive heat can reduce the lifespan of your battery. 
Many of the accessories on modern cars draw power from the battery even when your car is just sitting in the garage with the engine off. These "parasitic draws" include interior lights, door lights, faulty relays, the clock, the radio, and the alarm system all of which draw power from the battery.

Once your car battery is three years old, it is a good idea to have it checked annually at a Lithia Motors dealership while your car is in for service. Besides checking the battery itself, our factory-trained technicians will check the entire electrical system to make sure it is charging properly. We'll make sure the battery terminals are free from corrosion and tight, check the alternator for proper charging (it should be putting out 13.5 to 14.5 volts), and make sure there are no unusual drains on your battery.

When is it time to Replace your Car Battery?

Look for these signs to learn when it is time to replace your car battery. First, if your engine cranks slowly when you are trying to start the car. Instead of starting quickly with no trouble, the starter grinds and slows. If the battery is really dead, you will hear a clicking sound when trying to start the vehicle. That's never a good sign. It could mean a dead battery, a failing alternator, or both.

You may notice that your headlights are dim. That means the battery doesn't have enough power for the lights to shine properly. Your power windows might be operating slowly, or your windshield wipers might be creeping along. One of the first signs of battery problems is that electrical issues appear. You might even get unusual warning lights. Also, if you notice that the battery case appears to be swollen, have your car towed to a service center and have the battery replaced right away. This can especially happen after driving in extreme heat or cold.
Visit Lithia Motors for Battery Service
Our trained technicians at Lithia Motors can inspect and test your battery to see how much life is left and replace it, if necessary, with a battery that exceeds the manufacturer's specifications. No one wants to be stuck with a dead battery. Ongoing maintenance is the best way to prolong the life of your car's battery to keep you safe and on the road for the long haul.