What the best car battery has
- A strong warranty. Most brands offer at least a three-year replacement warranty. Some brands offer longer warranties, or a prorated refund if your battery dies within a certain time after the replacement warranty expires.
- Good reserve capacity. That's the built-in juice that lets your battery keep running when the car is off, such as if you leave your lights on. ConsumerReports.org tests this by buying dozens of batteries and running them dry; its ratings are the best source for finding a battery that won't conk out too quickly.
- Ample cold-cranking amps. Cold-cranking amps indicate how much power a battery has in frigid temperatures. Generally, more cold-cranking amps means a battery will reliably start up without repeated cranking on those cold early mornings. However, in professional tests, the number of amps doesn't always correlate with stronger performance.
- Long life. A good battery can last much longer than its three-year warranty. Read owner reviews to discover which batteries tend to soldier on the longest; some say their batteries have lasted nearly 10 years.
- A maintenance-free design. "Maintenance-free" means you won't have to top up your battery with distilled water. Some have a completely sealed case -- you can't open the battery at all. Others do have caps, so you can add water if necessary, but you shouldn't have to.
- A carrying handle. The average car battery weighs 40 pounds, so a carrying handle will prove extremely helpful, especially for do-it-yourselfers trying to lower the battery into a tightly packed engine compartment.
Know before you go
What size battery do you need? Batteries come in various sizes called "Groups." You can find what size to buy by checking out your current battery or by looking it up in your car owner's manual. Most stores can also let you know the size you need using your car's make and model. There are online tools that claim to do the same thing, but reports suggest they're not always accurate.
Do you live in a hot or cold climate? Choose your car battery accordingly. Hot-weather batteries, often labeled "South" or "S," are designed to endure extreme heat. Cold-weather batteries sometimes labeled "North" or "N" have higher cold-cranking amps (CCA).
Do you need a high-performance battery? Lead-acid batteries are still the most common type. However, an increasing number of new cars come with more advanced AGMs (absorbed glass mats), which can stand up better to heavy power drain. Fancy features such as electronic safety features, power outlets for mobile phones, and fuel-saving stop/start systems all increase your car's power use, so if your car is loaded with new technology, an AGM could be a good choice.
Do you drive off-road? Some batteries have fragile plates inside that can weaken or crack under heavy, continuous vibration. Others, such as Optima batteries, have sturdy coils that stand up better to constant vibration. Also, Optima batteries have a completely sealed case, so they're less likely to leak when jostled around than a battery with caps.
Do you want it installed? Garages, most auto-parts chains, and some other stores - including Walmart - will install your battery for free if you buy it there. Sears charges extra for installation (Est. $10), but promises to do it within 15 minutes or installation is free, and Costco doesn't install batteries at all. Some online retailers, including Amazon.com, can arrange for local installation of batteries bought online.
Choose a fresh battery. Like all batteries, car batteries lose strength as they sit on the shelf. Look on the case for a date, and make sure the battery is no more than six months old. ConsumerReports.org says the date is sometimes written as a code: a letter representing the month (such as "A" for January) and a number for the year (such as "6" for 2016).
Bring your old battery. When you buy a new car battery, the store will take your old one for recycling. In fact, in many states, you'll have to pay a $5 to $20 fee -- known as a "core charge" -- if you don't bring an old battery to recycle when you buy your new one (or within a specified time after the sale). States mandate the core charge to encourage recycling, which keeps the batteries' dangerous lead and acids out of landfills. And it works: Car batteries are the most recycled items in the world, according to the U.S. Environmental Protection Agency, with a recovery rate of 96 percent for lead-acid batteries.