ATLANTA » If batteries could go to a party, they’d wear blue suits and brown shoes and stand in a corner while the HDTVs and PCs whooped it up.

But that’s just because they’re shy. Batteries run the show when it comes to high tech. Without them your iPhone wouldn’t say a word, and your laptop computer might as well stay home.

Knowing a little bit about them can make a big difference in how well your gadgets work. It can mean having enough light to see when the power goes out and a few extra minutes to make a cell phone call when you need help. It can save you a few bucks, too.

Let’s start with the ordinary alkaline batteries you see at the checkout stand. They make the best choice for many everyday uses.

The reason is they can hold a charge even after being stored away for two or more years. A rechargeable battery, for instance, would be as dead as road kill if stored unused that long. By the way, while friends will tell you to store alkalines in the refrigerator for even longer shelf life, don’t bother. They’ll do fine in a closet or drawer.

And it’s smart to keep a dozen or so stored away. That way, if the power goes out you’ll have power for battery-powered lanterns, flashlights, portable radios and the like. They’re usually the battery of choice for smoke detectors. And small devices that don’t draw much power, such as remote controls, do best with an alkaline.

Rechargeable batteries have been around a long time, but there have been real improvements over the past few years. The old nickel rechargeables were highly toxic and didn’t hold a charge well.

Your laptop probably uses modern lithium-ion batteries—cell phones and other consumer gadgets have also almost universally moved to them. And, increasingly, they’re used in popular AA sizes in digital cameras and other devices.

They lose a charge when stored unused, but much more slowly than older rechargeables. And they avoid one of the big flaws of early rechargeable batteries: They have no memory effect. Batteries with memory effect needed to be completely discharged before charging again to remain effective. Still, I think it’s smart to let them run down to about 20 percent of their charge once a month or so.

Regular readers of the column know I’m a big fan of having an uninterruptible power supply—UPS—for a computer. It furnishes enough power to let you shut down your computer properly when the power goes out. But it’s also great during power failures as a source of AC current that will let you use the battery charger for your laptop and cell phone.

A UPS uses a sealed lead acid battery—not so different from the battery in your car. These batteries should be replaced every two years or so, and replacing the battery, rather than buying a new UPS, can save money. The manufacturer of your UPS will usually offer replacement batteries on its website.

You need to dispose of any outdated battery safely. Here is a site that offers tips on battery disposal: tinyurl.com/3yq64j.

Any type of battery can be a safety hazard if misused. For instance, popping an alkaline battery in a recharger, or using lithium batteries in a recharger made for other kinds of batteries, can be dangerous. For a long list of battery do’s and don’ts, check out this Web page: tinyurl.com/2f4k7yh.

Despite the improvements in batteries that I’ve mentioned, the technology has moved slowly compared with the high-tech world in general. But with the push for electric cars and the need to find ways to store energy produced by solar cells and other alternative energy sources, we’re on the verge of a great leap forward.

It’ll be fun to watch as batteries go from the wallflower at the party to the center of attention.