How to Choose a Car Battery
New car batteries are not a one-size-fits-all solution.
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Typically hidden away in your engine compartment, your automobile battery can feel a little neglected. But when it no longer has the power to crank your car to life, it’s time for a replacement — and there are a lot of different factors in finding the right battery for your car.
Different Types of Car Batteries: Lead-Acid or Absorbed Glass Mat
Since the earliest days of the automobile, the flooded lead-acid battery (also known as a wet cell battery) has been one of the most common car battery types. It uses an active solution of water and sulfuric acid in its cells to provide voltage, but it also requires new solution to be added once in a while, and it can leak if not installed properly, which is bad.
Newer alternatives are valve-regulated lead-acid (VRLA) batteries, which are sealed and don’t require additional liquids. A popular variant is the absorbed glass mat (AGM) battery, where the electricity-producing fluids are separated and absorbed by a fiberglass insert. The result is much higher performance, with faster charging and a longer life than a traditional battery.
Although there are more high-tech, expensive batteries out there for all sorts of special use cases — such as racing, or serious aftermarket sound systems — the majority of owners will be fine sticking with the kind of traditional lead-acid or AGM battery recommended in their owner's manual.
Is the Car Battery the Correct Size or Configuration for Your Vehicle?
You can be overwhelmed by the dozens of car battery sizes available at an auto-parts store, so the best advice is to check your owner’s manual to find the correct specs for your vehicle. Look for a number called "group size" for the right match. It’s critical that you use the correct battery size, since doing otherwise may make it difficult and thus unsafe to properly secure the battery and to run its positive and negative cables.
Even battery terminal locations vary between battery styles, so be sure to find a replacement that allows the proper connection to your existing cables. While most domestic and Japanese cars have posts on the top, many General Motors vehicles have posts on the side, and European cars often feature recessed top posts that make them different to install. Newer vehicles may even have additional modules that need to be detached and reattached.
How Extensive Is the Car Battery Warranty?
On average, automotive batteries begin to lose their ability to hold a full charge after three years, and often need to be replaced after five years. Most standard battery warranties only cover 24 months of use, but many manufacturers offer warranties as long as five years. Depending on the warranty coverage, you’ll either get a free replacement or a prorated amount toward a new battery. Just remember to keep your receipts and service records.
Cranking Amps vs. Cold Cranking Amps
Another spec to consider when buying a new car battery is the amount of startup amps the battery will be able to put out, depending on the air temperature. Cranking Amps (CA) refers to the amount of electrical current (amperes) that can be provided for 30 seconds at a temperature of 32° F (or 0° C).
Cold Cranking Amps (CCA) means the number of amps the battery can provide for 30 seconds at a more-frigid 0° F (-18° C). If you live in a northern winter climate, you may want a higher CCA-rated battery to help on those cold mornings.
