The AA test

The only things you can count on are death, taxes and never having the right type of battery when you need it. So when you drive to the store to pick up a pair of AAs, which brand should you purchase? We tested three different types of batteries by continuously powering a mini Maglite flashlight. The results were nothing short of illuminating.

Energizer Lithium
With technology becoming more advanced, shouldn’t the batteries step it up a notch? Though they are marketed for high-end devices, such as digital cameras and MP3 players, these lithium batteries lasted the longest in our flashlight test. With more than seven hours worth of flashlight power, you might want to consider spending the $2.50 a battery to fuel your high tech toys. Lithium batteries have the additional bonus of being environmentally friendly, unlike traditional lead- and alkaline-based batteries. When disposed of properly, lithium-based power sources pose little to no threat to the environment. The shelf life of a lithium battery is about twice the length of its alkaline cousin, and it weighs 33 percent less than normal AAs. While lithium batteries are certainly more expensive, the old adage applies: You get what you pay for.

USBCell
Your replica of a Star Trek tricorder screams geek, but a true geek isn’t only skin deep. Thankfully, ThinkGeek.com has devised a way to fuel your electronics and add geek cred. Sold as a two pack for $19.95, USBCell batteries are rechargeable through any USB port on a computer. Environmentally friendly and devoid of the recharging units that other brands require, USBCell offers freedom from dead batteries while away from home. In the flashlight test, USBCell lasted for only three hours—they require five to charge—so these won’t be your primary power source, but they work great in an emergency.

Kirkland brand
Is it really worth it to buy four dozen AA batteries in bulk to save a few bucks? Costco, a discount warehouse, offers 48 of their Kirkland brand batteries for $9.59—roughly 20 cents per battery. And there is no lack of power behind the cheap price. Two Kirkland batteries kept the flashlight burning for more than five hours. Even after five hours, you would still have 46 more, so the light could be going strong for 120 hours before you had to shell out another $10. Of course, now you have 48 alkaline batteries waiting to eat a hole in the earth.