Best Car Batteries for the Money

Identifying the CR Best Buys highlighted in our ratings starts with our test results. Each year, we purchase 150 individual batteries and put them through a grueling series of tests, measuring how they perform in extreme cold and heat and how long they will last if you leave your headlights on.

Our testers go to great lengths to evaluate the batteries. For example, battery life is measured by repeatedly discharging and recharging each battery about 3,000 times at a test temperature of about 167° F for 15 weeks or until performance drops to unacceptable levels. This simulates the hot under-hood conditions a battery can face during the summer, the toughest time of year for batteries because of the heat.

Absorbed glass mat (AGM) batteries tend to dominate our ratings. These pricey, maintenance-free batteries use a glass mat separator to move the electrolyte solution between the thin battery plates. AGMs are built to better stand up to repeated draining and recharging cycles than traditional lead-acid (aka “flooded”) batteries. AGMs are becoming standard equipment in more cars because modern features such as fuel-saving stop-start systems, electronic safety and convenience features, and power outlets for mobile electronics increase the demand for power. You should replace the battery in your car with the same size and type, but you can upgrade from a traditional battery to an AGM battery.

“If you live in an area with extreme temperatures and are looking for a maintenance-free battery, consider getting an AGM,” says John Banta, senior test project leader at Consumer Reports. “High heat can affect the life of AGM batteries, much like flooded batteries, but they tend to perform better overall in our tests.”

If you don’t need the capability to meet those demands, you can find traditional flooded batteries that are a better value. Our analysis has found that a traditional battery is the better buy in most categories we rate.

Below, we present Consumer Reports’ Best Buys—the best car batteries for the money—in these sizes: Group 24/24F, Group 35, Group 47 (H5), Group 48 (H6), Group 49 (H8), Group 51R, and Group 65. These group numbers indicate battery sizes, in the same way AA and AAA indicate the sizes of batteries you’d use to power home electronics.

Size 24/24F (top terminal): Fits many Acura, Honda, Infiniti, Lexus, Nissan, and Toyota vehicles.

Size 35 (top terminal): Fits most Japanese nameplates, including many recent Honda vehicles, most Subaru vehicles, and most Mazda, Nissan, and Toyota vehicles.

Size 47 (H5) (top terminal): Fits many Buick, Chevrolet, Fiat, and Volkswagen models.

Size 48 (H6) (top terminal): Fits many vehicles from Audi, BMW, Buick, Cadillac, Chevrolet, GMC, Jeep, Mercedes-Benz, Mini, Volkswagen, and Volvo.

Size 49 (H8) (top terminal): Fits many vehicles from Audi, BMW, Hyundai, and Mercedes-Benz.

Size 51R (top terminal): Fits many vehicles from Honda and Nissan.

Size 65 (top terminal): Fits large cars, trucks, and sport/utility vehicles from Ford or Mercury.