Each year Consumer Reports testers put car batteries through, well, a battery of tests.
The batteries are continuously drained and recharged until they can't start a car, chilled to zero degrees and even subjected to more than 160-degree heat, all to see which ones work best.
Consumer Reports tested nearly two dozen batteries with name like DieHard, NAPA, and Duralast. Traditional batteries cast about $70. A new type of battery called an absorbed glass-mat battery, or AGM cost $180.
Why is it so much more expensive?
"These batteries contain absorbent fibrous glass material that can make them last longer, " said Consumer Report's John Galeotafiore. "They're also sealed and spill proof, which can make them safer and conventional batteries."
Most of the AGM batteries outperformed traditional batteries.
Another plus with the AGM batteries, they're maintenance free. You don't have to refill them with distilled water like you do with some regular batteries. That's particularly important if your battery is tough to get to.
Consumer Reports says when getting a new battery, it's important to check the manufacturing date.
"You don't want to buy a battery that's more than six months old because they lose strength when they're sitting on the shelf." said Galeotafiore
Some batteries have an obvious manufacturing date. Others use a letter for the month, like "A" for January, followed by the year.
And it's a good idea to get your battery tested at least every four years so you're sure it's got enough power to get you where you want to go.
Consumer Reports says be aware, there are a number of things that can shorten the life of your car battery. For instance, if most of your driving is short trips, your battery doesn't get enough time to recharge. And living in a hot climate is tough on auto batteries.