Automotive 101: The Battery is the Life Force of Your Vehicle

Automotive 101: The Battery is the Life Force of Your Vehicle
Image: Pixabay
November 24, 2014

Car battery causing headaches? What's so special about a car battery, anyway?

The battery is the life force of your car. Without it, you would not be able to have power to do anything from starting the engine in subzero temperatures to cruising down the highway on a sunny day. Sure, the engine does a lot of work and it should get credit for what it does. But without the battery, your engine would just be a several thousand dollar paperweight.

How Does a Battery Work

Your car's battery depends on the terminals to make a connection to the rest of the electrical system, the starter to turn the engine, and the alternator to slowly recharge the battery. Contrary to popular belief, your car runs primarily from the stored power in the battery, not the alternator, which can take up to thirty minutes of highway driving to fully recharge a battery.

Vehicles that operate a lot of accessories and make frequent short trips may not fully charge and may experience 'dead' batteries every few weeks. An older battery will typically not perform as well as a newer battery, so these symptoms might increase as the battery ages. A battery with low power may even cause your vehicle to stall because the alternator, no matter how good it is, doesn't have the power to run all of your systems and charge the battery at the same time. You may even damage the alternator in this way by running it at 100% all the time.

Batteries typically last anywhere between three years and five years, with some lasting seven years or more. Just like the rest of your car, maintenance can have a big impact on battery life. Make sure to follow all recommended maintenance on your battery, such as ensuring adequate fluid levels and keeping the terminals clean.

Battery Warranties: Batteries Installed by the Car Manufacturer

Many batteries have warranties of five years or longer, but your battery might not last that long depending upon your driving conditions. So what should you understand about your battery warranty before you have a problem?

If you have a battery that is covered under your car manufacturer's warranty, you likely aren't getting as much peace of mind as someone who buys and installs a battery outright. Despite most vehicles being covered for three years or 36,000 miles from the date of purchase under the 'bumper-to-bumper' warranty, batteries are consumable items and typically have a warranty of only two years or 24,000 miles depending upon the vehicle manufacturer. After that time, you may have a pro-rated warranty or no warranty at all. Check your car's warranty manual to determine the warranty coverage for your battery. If you suspect a battery problem and are still covered by warranty, get your car checked out before your warranty expires.

Battery Warranties: Batteries Installed by You or a Third Party

As for batteries that don't come with the vehicle, there are varying differences out there. One of the biggest differences is cost, but it's easy to simplify matters if you think of the cost as the price of the battery plus the cost of the battery warranty.

You may see some more expensive batteries listed as having a five year warranty over the standard two year warranty on another of the same brand, but what does that mean? You may see confusing terminology, such as 'silver' or 'gold,' or you may have a part counter employee trying to get you to upgrade. The basic difference here, assuming the batteries are identical, is that you're paying a little extra money now to have an extended warranty on that battery. But is that longer warranty worth the extra money upfront? Usually, extended warranties are not worth it and we typically recommend against extended warranties. Batteries are no different.

Regardless of the length of the warranty you purchase, batteries are usually prorated after a few years. Let's take a hypothetical five year warranty. The first two years may be 100% replacement, but for each month past two years up until five years, the amount the manufacturer will reimburse you for a failed battery decreases each month. If your battery was $100 and your battery fails a month before the five year warranty expires, you might be shelling out $97 with the manufacturer contributing only $3. If you paid an extra $20 for that extended warranty, you're losing money. A longer warranty doesn't mean that the battery will perform better or last longer.

In any case, the service center or parts department will have to verify your warranty. If records aren't on file, you may have to provide your receipt, which can get lost after a few years. Make sure you keep your receipt in a place you can easily find it. Don't rely on the plastic pockets sometimes attached to the battery. What happens if the battery leaks acid? That's right. Your receipt is gone. Keep your receipt in your car and take a good quality photo. In time, receipts seem to fade and become illegible.

I Suspect a Problem

If you suspect that your battery might be going the way of the dinosaur, don't just replace it. Have it tested! Many auto parts stores offer free battery testing, so it's easy to get your battery tested every few months when popping in for a set of wiper blades.

A word of caution if you decide to have your battery tested by a parts store: some store associates work on commission and are dishonest. When testing your battery, make sure the associate inputs the correct Cold Cranking Amps (CCA) number from your battery label into the tester. If the associate accidentally inputs a baseline number too high, your battery will fail the test, even if it is perfectly fine. If you doubt the test, take it somewhere else! You may even find out that your battery is fine but another component is either drawing too much power or your system isn't generating enough power. Just remember that parts store associates are not mechanics and don't have the mechanical know-how to properly diagnose a problem. If they were mechanics, they wouldn't be working at a parts store!

Signs to Have Your Battery Checked

Engine Cranks, But Doesn't Start

Most people reach for jumper cables when the car cranks but doesn't start. In many cases, the battery has discharged and isn't able to start the car. But that's not always the case. If the car seems to have a lot of juice and can turn the engine over rapidly, the battery may not be the culprit.

Three things are needed to start a car: power, air and fuel. If the car doesn't start, it's not getting enough of one of these items. You can always give the horn a quick press to see if it sounds good and loud. If it's weak or doesn't work at all, you aren't getting enough or any power from the battery. If the battery has died, run the car for a sufficient enough time to recharge the battery with any unneeded accessories off or have it recharged with a charging device. You may have to drive on the highway to get enough of a charge to start it again later. Definitely have your battery and charging system checked at this point.

No Power to the Vehicle, Such as Lights, Horn, Etc

As mentioned in the previous section, a weak or inoperative horn indicates that not enough power is making it to the vehicle. But what if you are already driving and suspect you have a weak battery? Are your headlights flickering or getting dim? Is your radio turning itself off and on again? Does it feel as if you are going to stall? There is a good chance that you aren't getting enough power! If you suspect that you aren't getting enough power, you should immediately turn off any accessories you don't need in order to conserve enough power to get your car to a safe place. You'll have to have your battery and charging system tested. You might even be pleased to learn that your battery tests fine but has a buildup of corrosion on the terminals prevent power from getting to where it needs to go.

Hard Starting in Cold Weather

When the weather gets colder, your battery has to work much harder to start the car. Cold weather reduces conductivity, which means not as much power is making it through the wires and cables as would normally happen in the summer. If you are experiencing hard starts when it is cold out that seem to improve when it gets warmer, you definitely need to test the system. Make sure that the Cold Cranking Amps (CCA) rating on your battery is sized appropriately for your vehicle.