So if you see a good article on batteries, you may want to give it a look. Here's a discussion from YahooFinance written by Althea Chang February 21, 2010 with mainstreet.com
Store brands may save you money on household necessities, but generic batteries might not be your best bet, according to recent tests comparing name brand and store brand batteries.
CVS AA Long Lasting alkaline batteries didn't actually last longer than other batteries tested under the same conditions by Consumer Reports. In fact, those generics had less than half the power as Panasonic Evolta alkaline batteries, Consumer Reports found.
Among the longest-lasting AA batteries overall were Energizer's Ultimate single-use lithium batteries, which took 678 pictures before dying, compared with 92 shots taken with a camera using the CVS batteries. As a group, lithium batteries lasted the longest, but budget-friendly rechargeable batteries performed nearly as well, Consumer Reports said.And rechargeables like those made by Energizer and Duracell could be your best bet for use in digital cameras and favorite toys, Consumer Reports suggests.
For remote controls, flashlights and other devices, alkaline batteries might be your best bet since their charge could last you several years, while rechargeable ones can lose their charge over time, as MainStreet previously reported.
Consumers may not want to rule out store-brand batteries completely, however. Kirkland Signature AA batteries, sold at Costco only in packs of 48, lasted nearly as long as the Panasonic batteries, according to Consumer Reports.
Interesting to see that "budget friendly rechargeables performed similarly to long life lithium ion
Here's a good article from Backpacker.com(by Berne Broudy December 07) on the selection of rechargeable batteries available:
Worldwide, 15 billion disposable batteries are born each year. When they die, they mostly end up in landfills, where toxic mercury and heavy metals leach into soil and water. Battery makers are trying to do better–by reducing heavy metal content and figuring out how to recycle it. But according to Shelley Minteer, a battery specialist and electrochemist at St. Louis University in Missouri, "the technology is advancing at a snail's pace." While many towns have instituted "Hazardous Waste" days when you can drop off dead soldiers, experts say that rechargeables are the best solution now. Here's a quick primer on the most common types:
NiMH (nickel metal hydride) batteries have no toxic ingredients and last three to four times longer than alkalines. They work well in cold weather and come in a multitude of sizes. That said, they're more expensive than alkalines (about $8 for four AAs at all-batteries.com, not including shipping or the charging unit), they discharge quickly when not in use, and they lose staying power with each recharge.
NiCD (nickel cadmium) rechargeables are becoming obsolete due to their relatively poor performance, highly toxic cadmium, and inconvenient disposal requirements (you must dispose of them via the manufacturer or a specially equipped recycling center).
Zinc air batteries are non-toxic and are widely used in hearing aids. While they only come in coin-size configurations, they work in some watches and mini-lights, and Minteer says new shapes may come soon. Since this technology requires airholes in the device, zinc batteries aren't the choice for weather-exposed applications.
Lithium ion rechargeables are ideal for backpackers because they're small, light, long-lasting (up to 300% longer than alkalines), high voltage, and hold a charge for a long time. Downsides: They're pricey–four AAs cost about $30 on sale at all-batteries.com, not including shipping.
What's next? Minteer and others say there's a new type of battery in development that promises to be the greenest of them all. In three to five years, watch for one that runs on sugar-eating microorganisms and comes in a variety of configurations to power everything from a GPS to a computer. For more info, visit greenbatteries.com or earth911.org.