Your remote control needs them. So do toys, flashlights, wall clocks, milk frothers—even many smoke alarms. Batteries keep the juice flowing. And while our gadgets have become increasingly sophisticated, charging or swapping out their batteries is still a necessity.
But not all batteries perform as promised—even those from well-known name brands. Use this guide to learn about the types of batteries that are available, and which will work best for your needs.
Prices and performance range widely among AA batteries. We test disposable AAs because they are the most commonly purchased battery for household items like calculators, portable clocks, garage door openers, even your wireless mouse. To find out whether you need to pay top dollar to keep your gadgets running, we recently tested 15 different brand-name batteries—both alkaline and lithium.
Our tests were designed to mimic typical usage in toys and flashlights. For toys, we simulated an hour a day of play. For flashlights, we tested the battery for 4 minutes every hour for 8 hours, and then left it alone for 16 hours. We repeated each test until the batteries were drained.
The full test results on each battery model are available to subscribers. But our testing also showed a lot about how different batteries technologies perform, and that information is below.
First, here’s a note on shelf life: Alkaline batteries can be stored for five to 10 years; for lithium batteries, it’s 10 to 15. And unlike the old carbon-zinc batteries, modern batteries don’t benefit from being refrigerated.
While typically rating highest in performance, lithium batteries can also be expensive. Because of lithium’s higher stability—lower "self-discharge," or power loss—use them for high-drain devices, or for devices that are hard-to-reach or less commonly used. Compared to alkalines, lithium batteries are less likely to release a corrosive liquid as they age.
The top-rated alkaline batteries we tested rated on par with lithiums. A number of other brands scored high enough to merit recommendation. In many instances, you can save money by choosing a well-manufactured alkaline battery for low-drain devices such as toys, travel clocks, or an often-used remote control.
These tips will help your batteries last longer, and make sure you stay safe. Alkaline and lithium batteries are relatively benign household items. But they do present some dangers if they’re used or disposed of incorrectly.
• Store batteries in a cool, dry place.
• Each time you put in new batteries, clean the contact surfaces and battery compartments by rubbing them with a clean pencil eraser or rough cloth.
• Remove batteries when you don’t expect to use a device for a few months.
• When more than one battery is needed in a device, always use batteries of the same type, brand, and age.
• If a battery leaks, and its fluids make contact with your skin or get into your eye, rinse well with plenty of cold water and seek medical attention.
• Don’t carry or store loose batteries along with metal objects—say, in a change-filled pocket. This could short-circuit the batteries. Tote your spare batteries in a small ziplock bag.
• If a battery feels hot, changes color or shape, gives off an odd smell, or seems abnormal in any way while in use or in storage—don’t use it!
• Don’t try to recharge nonrechargeable batteries. They can explode. It’s also a bad idea to install them backwards, get them wet, expose them to fire or heat, pierce them, or strike them with a heavy object.
Rechargeable lithium batteries are a greener choice than alkaline. Consider high-capacity rechargeable batteries for devices that are used a lot, such as game controllers. Rechargeable batteries of about 2,000 milliamp-hours or more work best. The initial cost is high, because you also need to buy a separate charger, but they’ll eventually save you money in devices that you use frequently.