Impeccable in every way, the DieHard Advanced Gold 50778 (Est. $165) wins first place in a leading test. It gets the highest scores in every category: reserve capacity, or how long it will run with the engine off, such as if you accidentally leave your lights on; hot-climate endurance; and cold-cranking performance at 0 degrees Fahrenheit.
Different cars take different size batteries. The best-reviewed version of the DieHard Advanced Gold is a Group 78 size that fits many large Chrysler and GM vehicles. The Group 34 version does just as well in tests, and the Group 94 version gets good customer reviews at Sears.com. One user says the car lights seem brighter now, and another was able to immediately jump-start three vehicles when other batteries couldn't do the job. But be careful: A smaller Group 48 version of this battery (model 50748) died quickly in the heat and finished dead last in expert testing.
Another plus is a strong warranty. If your DieHard Advanced Gold battery fails to hold a charge within three years, Sears will replace it. For 100 months after that, you'll get prorated credit toward a replacement if your battery conks out.
Runner-up Interstate Mega-Tron Plus MTP-24 (Est. $125) is another battery that stands up well. It aces a hot-climate endurance test conducted by one reviewer, and owners say it easily withstands all kinds of real-life abuse. One user reports that he repeatedly gets six years of car battery life out of Interstate batteries in the scorching Arizona heat. Another says his eight-year-old Interstate battery still starts even if he leaves his dome light on all day.
The Interstate battery also does very well in cold-cranking and reserve capacity tests, just a notch below the pricier DieHard battery.
Again, watch out for sizes: The MTP-24 is a battery in the Group 24 size, sized for many Japanese imports such as Toyota/Lexus, Honda/Acura and Nissan/Infiniti. The Group 48 version tests just as well, followed closely by the Group 35 size. However, the Group 75 version earns just middling scores for reserve capacity and cold cranking, but still gets the same exceptionally long life.
If you don't mind installing your own battery, check out our discussion of Cheap Car Batteries below. The best-reviewed Kirkland Signature 12866 performs just as well as the best expensive batteries, but it's sold only at Costco. You'll need a paid membership to shop there, and they don't install batteries.