Your car battery supplies the electrical current that the starter motor needs to crank the engine. It powers components and accessories when the engine is not running and, when electrical loads temporarily exceed the car’s charging system capacity, the battery supplies the needed extra current. The battery also acts as a voltage stabilizer for the entire electrical system.
Today’s vehicles have more electrical demands than ever before, and batteries play an essential role in meeting those demands.
Two types of car batteries
While manufacturers are always working on improvements, today’s car batteries generally fall into two basic design categories:
• Flooded lead acid (FLA), which has been the standard for decades
• Absorbent glass mat (AGM), a newer design that offers advantages in specific applications
The right battery for your car
The flooded battery and glass mat battery serve the same basic function, but do not work interchangeably. It’s important to consult your owner’s manual before you purchase a replacement battery.
If your car has a start-stop system that shuts down the engine while you’re stopped at traffic lights, you likely need an AGM battery. This design ensures proper operation of the start-stop system while maintaining maximum battery life. If your car came with a FLA battery, replace it with the same type when needed. There is no need to spend the additional money for an AGM battery.
Car battery care
While most modern designs claim to be maintenance free, there are a few things you can do to get maximum life out of a battery. You can complete these steps yourself, or ask your auto service tech when you bring your car in for routine maintenance.
Check and clean the corrosion from each battery terminal. Corrosion could compromise the electrical connections.
Check and tighten the mounting hardware so the battery does not move around when the car hits bumps in the road. Excessive vibration is a detriment to battery life.
Replacing a weak or dead battery
Even though the alternator keeps it charged, there will come a time to replace the battery. Car batteries last three to five years typically depending on a few different factors, such as climate. If you live in a location where higher average temperatures are the norm, you can expect more frequent car battery replacements.
After the second year, it’s a good practice to have your auto tech do an annual test to determine the battery’s remaining energy capacity. It’s far better to identify a weak battery in the service bay than to have a dead battery out on the road.
When it’s time for a new car battery, the technician should first connect a supplementary 12-volt power supply before disconnecting the battery cables. This will keep onboard computers operating properly. Complications could be significant if this step is not taken.
If battery power is lost, not only will the radio and seat memory settings need to be redone, but also, on more sophisticated vehicles, some computer systems will need to be reprogrammed, which could be a costly service.
On some vehicles, the charging system must be reset with every battery replacement to prevent premature battery failure, so it’s important to choose an auto service professional who has experience working on your make and model car.
Choose the right auto service professional
AAA makes it easy with open access to its network of more than 7,000 Approved Auto Repair facilities. Each AAR location meets AAA’s high standards for tech training and certification, customer satisfaction and more, taking the guesswork out of finding the right auto service professional.
Want to know approximately what a repair will cost. AAA provides an easy-to-use online tool that calculates the estimated price including parts and labor and the AAA member discount.
AAA Mobile Battery Service
If your car won’t start when you turn the key, turn to AAA for convenient mobile battery service. Whether you’re stranded in your driveway, a parking lot or on the road, a professional car battery service tech will come to your location, conduct a free diagnostic test of your car's battery and starting and charging systems, and if needed, install a new battery on the spot. AAA also takes care of proper disposal and recycling of the replaced car battery. For more information, visit AAA.com/Battery.