A good passenger car battery should start right up -- year after year -- whether it's blisteringly hot or blustery cold outside. It should also have plenty of juice to spare (for those times when you accidentally leave your lights on). Of course, if you've got a high-performance car tricked out with lots of electronics, you might need a high-performance car battery (covered below) -- or, if your budget's tight, a reliable cheap car battery could do the trick. But for the average passenger vehicle, a solid, dependable, tried-and-true mid-range car battery is the best choice.
Impeccable in every way, the DieHard Advanced Gold 50778 (Est. $175) has aced a leading test for several years running. 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 and Group 65 versions do nearly as well in tests, and the Group 94 version gets good customer reviews at Sears.com. 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.
More pluses: a sturdy design and a strong warranty. This is an absorbed glass mat battery, which "typically makes for a more rugged and longer-lasting battery than a conventional battery," ConsumerReports.org says. If your DieHard Advanced Gold battery fails to hold a charge within three years, Sears will replace it.
One drawback: Sears charges $10 extra for battery installation, according to Sears.com. Plenty of other stores -- including Walmart, auto-parts chains and some garages -- will install your battery for free if you buy it from them.
The Optima RedTop 78 (Est. $155) doesn't appear in expert tests, but it's a favorite of car owners -- they award it high scores in reviews at Amazon.com and the Advance Auto Parts website. Like the DieHard Advanced Gold, the Optima RedTop is an AGM (absorbent glass mat) battery -- considered more durable than ordinary "flooded" batteries -- with a three-year warranty. However, we did see complaints that Optima failed to honor warranties of batteries purchased on line. The company's warranty guide includes a disclaimer that batteries purchased through "unapproved channels have no warranty whatsoever."
There are some differences between these two batteries. While Sears markets the DieHard Advanced Gold as a "deep cycle" battery (capable of being drained and recharged, over and over), Optima markets the RedTop as a "starting" battery (pumping out a big load of power to start the engine quickly). Accordingly, the RedTop's cold-cranking amps are just a bit higher than the DieHard's (800 versus 775), while its reserve capacity is a bit lower (100 minutes versus 120). Several owners report that their vehicles really do start faster with the Optima RedTop, while others note that their cars start reliably after sitting idle for months at a time.
We give the DieHard Advanced Gold 50778 a slight nod as our Best Reviewed selection thanks to its sterling performance in expert tests, but the Optima RedTop 78 is very much worth considering. The bottom line is that both batteries are good choices for the average vehicle: Either battery will start your car promptly, and won't conk out terribly soon if you forget to turn off the headlights. Owners give both batteries high marks.
High-performance batteries are pricey, but are worth it for heavy-duty use. You might want such a battery if you have a custom sound system or other accessories (like winches) that draw a lot of power, or if your kids like to watch your car's DVD system while the engine is off.
Many users consider the Optima YellowTop D34/78 (Est. $200) -- with its standout bright-yellow lid -- to be the leader in this premium category. The YellowTop is a combination of a starting battery and a deep-cycle battery. Draining a standard car battery of all of its charge can shorten car battery life. On the other hand, a deep-cycle battery can withstand that type of abuse, even if done on a somewhat regular basis.
Depending on the retailer or the reviewer, this battery is also known or marked as the 8014-045, 9014-045, 27991, D34-78, D34/78-950, YEL34/78, 989237, SC34DU, 3478DT or N9934/78YEL; all are the exact same battery. It excels in one leading test, landing just behind the winning DieHard Advanced Gold 50778 discussed above. Like the DieHard, the YellowTop plows through blistering heat and bitter cold with ease. Interestingly, the DieHard delivers a bit more power when the vehicle is off, known as reserve capacity, than the YellowTop in that test. But in real life, owners say the YellowTop is king for power-hungry accessories and lights. Optima even recommends its YellowTop batteries to run tractors and forklifts. It's also perfect for off-roading, experts say, because instead of fragile plates inside, the Optima battery has sturdy spiral tubes that stand up to constant vibration.
This pricey battery might be overkill for ordinary cars and ordinary uses, but many owners wouldn't buy anything else. For example, the Optima D34/78 earns nearly perfect ratings from more than 180 owners at AdvanceAutoParts.com. Owners overwhelmingly love the YellowTop D34/78 at Amazon.com, too, where it earns 4.8 out of 5 stars based on more than 120 reviews. While praise is not quite unanimous -- some say they've had YellowTops fail quickly -- such complaints are the minority. Plenty of owners say that one YellowTop has lasted through a decade or more of hard use; it carries a three-year warranty, but as with the Optima RedTop, if you buy this battery through an "unapproved channel," it might not be honored.