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How long does a car battery last? (part 1)

J&H Automotive

Series: car battery | Story 1

How long does a car battery last? Mechanics will often joke that the answer to this question is: until it doesn’t work. While that’s not a response that inspires confidence, there is some truth to it. There are many variables that come into play when figuring out a battery’s lifespan.

Sometimes, you’ll buy a battery that seems to never quit. Other times, the battery throws in the towel after just a few years.

In this guide, we’ll cut through some of the clutter surrounding the lifespan of car batteries, including how long they usually last, what impacts their longevity, when you need to replace the battery, and how you can prolong your battery’s life.

How long does a car battery last?

On average, your car battery should last about three years, but the general range of a battery’s lifespan is two to six years. Let’s review some of the most common variables that affect battery life.

Initial battery build quality

You know the adage “you get what you pay for,” and this rings true for car batteries. If you head to the local discount store and pick up the cheapest battery possible, it could have inferior components and manufacturing processes that lead to more battery problems.

Battery age

No, we’re not talking about how long the battery’s been in the vehicle. We mean how long it sat on the shelf in the store before being sold. Even when sitting idle on a store shelf, a battery is losing life. If you buy a new car battery from a volume seller, then you can be confident it hasn’t been sitting on a shelf for long. However, if you buy a battery from a small shop with little traffic, there’s a good chance it has exhausted most of its battery power while collecting dust.

Where you live

Where you live significantly impacts a car battery’s life, particularly if there are extreme temperatures. Heat is a battery killer as it increases the degradation rate.

Don’t get too confident, though. Car batteries are no cold-weather fans either. A fully-charged battery can feel significantly weaker during icy winters.

Battery positioning

Have you ever opened your hood to find no battery? Sometimes a car battery is found in the wheel well or even in the trunk. This isn’t for the sake of weight distribution, but rather to help your vehicle’s battery last as long as possible.

Moving the battery from the engine bay to a cooler environment will dramatically increase its lifespan. The trunk has become a favorite place for many automakers, as it’s away from the engine’s heat and still easy to access.

Battery installation

Vibration can speed up the breakdown of your vehicle’s battery. Most cars have a battery hold-down system to minimize vibration, but some owners don’t realize how important this is and never reinstall it when replacing a battery. Without this hardware, your battery will vibrate and sometimes shake violently, which can lead to a dead battery in no time.

Vehicle’s mechanical health

The mechanical condition of your car can have a huge impact on battery life. Your battery relies on the transfer of engine power to the alternator, which generates electricity to charge the battery and run the electronics while the engine is running.

The alternator should usually generate 13.5-14.5 volts. Of that power, approximately 12 volts run the vehicle electronics — computer, fuel injection, car radio, air conditioner fan, headlights, etc. — and the remaining 1.5-2.5 volts flow to the battery as a maintenance charge.

If there’s a breakdown in this system — be it a bad belt, bad alternator, or bad wiring — your battery may not receive ample charge and endure excessive stress. This can reduce the battery’s lifespan.

Driving habits

Your car’s battery requires frequent maintenance charging, and your alternator can handle this on mid-range and long trips (i.e., those 10 minutes or longer). However, if you typically take only five-minute trips to the grocery store and back once a week, you could be shortening your battery’s lifespan.

Starting the vehicle is the most stressful point for a battery because this is the only time the battery does 100% of the work. Otherwise, the battery acts as more of a passthrough and a storage unit, capturing excess power from the alternator.

If you start your vehicle and take a short trip down the road, you’ve put the battery under immense stress to start the vehicle without driving far enough for the alternator to recharge it. Doing this repeatedly can dramatically limit the battery’s life.

What can you do if your battery dies?

It happens to almost every car owner at least once: You head out to your car, turn the key, and you get nothing but clicks or a slow cranking sound. It’s a dead battery.

What’s next?

Do you have to go buy a new battery?

Not necessarily. You can use another vehicle or a battery-powered jump pack to jumpstart your vehicle. This is when you use an outside power source, like another car’s electrical system or a battery, to start your vehicle. From there, your vehicle’s alternator can take over.

In many cases, your car will fire right up and work fine from that point forward. However, there are times when a jumpstart isn’t enough, and you’ll need to replace your battery.

More information on batteries to come next time in part 2. For more information please consult the knowledgeable technicians at J&H Automotive. The shop is located at 501 W. Tehachapi Blvd. and can be reached at (661) 822-9171.