I lurk in a wider group of NGs then I ever post in. sci.geo.satellite-nav is a GPS (there are other satellite nav systems but GPS is the most common) NG. LG hangs out there. A guy wrote an interesting article on batteries. A lot of us use batteries for many usefull activities. It agrees (mostly) with my own studies and experience.
Matching the Battery to the Task
By DAVID POGUE
IF the F.B.I. ever singled me out for surveillance, its final report wouldn't hold much interest. "Wife, two kids, dog. Watches `Survivor.' Aversion to mayo." Only one line at the end of the document might seem a little peculiar. "Buys AA batteries by the gross."
These days, most gizmos digital cameras, palmtops, music players seem to have been designed in a conspiracy with Duracell: they guzzle batteries like Gatorade at the marathon finish line. And it's not just me. According to an Industrial Market Research survey, the average American has about 25 battery-operated gadgets in the house, up from only 7 in 1987.
The battery makers, of course, are delighted. All around us, we see ads for new kinds of batteries that "offer unsurpassed power for today's demanding devices," "last longer on high-tech devices" and have "longer service life." In the name of science, I decided to perform a few simple tests: I'd pop sets of each heavily hyped battery into, say, a Palm organizer and see how long they took to run down. What could be more scientific?
As it turns out, almost anything. When I shared my plans with representatives of the Big Three Duracell, Eveready and Rayovac they told me, with the weary sighs of people who explain this point to journalists every day, that battery run-down tests are terribly misleading. For starters, a battery designed to excel in such a test would do poorly in the real world, where people play, pause and put aside their electronics for days or weeks. Who on earth actually runs a gadget continuously until it's out of power? (Game Boy owners, you can put your hands down.) Furthermore, the battery makers say, there is much greater inconsistency in the power consumption of supposedly identical devices than between two different batteries.
"We'd be delighted to help you design valid tests," one battery company representative said. "And we'll look forward to reading the results around Christmas."
When people conduct proper battery tests the repetitive, expensive, computer-controlled sort prescribed by the American National Standards Institute they find little variation across brands. One such test, published by Consumer Reports in March, offered a straightforward conclusion: When you need standard alkalines, ignore the marketing; just buy the cheapest ones.
Whatever size you're looking for, from tiny AAA's to fat C's and D's, the hard part is figuring out whether to buy the standard alkalines or some other type. Until 1980, you had only one type to choose: the silver "heavy duty" batteries, like the Eveready types with the black-cat logo. But that era is long over.
What replaced those old "standard" batteries is a wide and confusing range of higher-powered battery types: alkaline, premium alkaline, rechargeable alkaline, nickel metal hydride and lithium. (All told, 92 percent of the batteries sold nationwide are alkalines, which offer from two to six times as much life at roughly the same price as the old "heavy-duty" type.)
It would feel glorious to declare one type the winner and then rent a movie to celebrate. Alas, batteries aren't that simple.
In general, you can break down today's battery-operated devices into three categories. First, there are low-drain gadgets that sip power with all the gusto of an elderly aunt at afternoon tea: radios, clocks and flashlights that you keep on hand only for emergencies.
The vast majority of today's electronic gizmos fall into the moderate-drain category: tape recorders, Game Boys, music and CD players, electronic toys, pagers, boomboxes, smoke detectors, remote controls and flashlights that you'll use a lot when camping, for example. The third category, high-drain devices, has only a few occupants like digital cameras, palmtops, remote- control toys, portable televisions and photo flash units but is likely to see more arrivals in the next few years.
Once you've grasped that much background, buying batteries is fairly simple: for low- and medium-powered equipment, standard alkalines offer the best power per penny.
Battery selection for high-drain gear, however, is where the game gets interesting. In a typical digital camera, standard alkalines might last all of 30 minutes, as many a crestfallen consumer discovers.
That's why some companies are touting something called premium alkalines reformulated batteries designed to last longer than standard alkalines in high-drain gadgetry. (The improvements include, as Duracell puts it, "proprietary separator material, enhanced cathode design and a high-power anode composition," just as you probably suspected.)
Duracell, for example, says that its premium battery, called Ultra, lasts up to twice as long as standard copper-tops in high- drain electronics. (Energizer's E2 line is also a premium alkaline, but Consumer Reports says it's not much more powerful than standard alkalines.)
On the other hand, Ultra isn't as effective in medium- or low-drain electronics, offering an improvement of less than 50 percent, Duracell says, over standard alkalines. Any improvement is welcome, of course, but remember that Ultras cost about $1 apiece in a multipack, twice the price of store-brand regular alkalines. In other words, the convenience of Ultras is worth paying for in your Palm, television or digital camera but may be a waste of money in ordinary devices.
But even premium alkalines can't power a digital camera for more than about 60 minutes of shooting, viewing and deleting pictures still not enough to last the whole day at Six Flags, let alone your two-week vacation.
The final step up, therefore, is lithium batteries (not to be confused with lithium-ion laptop batteries) very expensive cells ($10 for four) that last five times as long as standard alkalines in high-drain electronics. Only Energizer makes AA lithiums. Duracell makes a lithium power pack called CV3 that looks like two AA batteries fused together, but it fits only certain digital camera models from Casio, Kodak and Olympus, for example, that have been designed to accept them.
If you use a high-drain device almost every day (this means you, palmtop and digital-photography addicts), the ultimate solution to the battery problem is nickel metal hydride (NiMH) batteries. Not only do they last even longer than premium alkalines, but for the ultimate in economy, you can recharge them 500 to 1,000 times by snapping them into a charger plugged into the wall.
Rayovac's superb $30 charger (for AA, AAA and 9-volt sizes) rejuvenates drained NiMH's in one hour or less, a great improvement over previous chargers. (You'd think that engineers would have devised a shorthand for this battery's name, so they don't have to spend their days shouting, "Yo, Frank, should I put these nickel metal hydrides over on the nickel metal hydride shelf?" But they haven't.)
The trouble with NiMH's is that they lose their charge over time about 15 percent per month. That makes them poor choices for long-term locations like remote controls, smoke detectors, digital cameras used only occasionally and, for that matter, the kitchen battery drawer. Some people keep one set in the charger and a second set in the camera, so they're always ready; but that's a lot of complication. At this point, rechargeables (including rechargeable alkalines, short-lived batteries that you can recharge only a few times) represent only 1 percent of battery sales. On the other hand, it's the fastest-growing battery category.
If you'd like to minimize complexity and maximize economy, then, the bottom line is this: Buy standard alkalines for everyday gadgets. Cheap store brands generally do just as well as big-name brands. In digital cameras, palmtops and other high-powered gizmos, buy rechargeable nickel metal hydrides (for gear you use daily) or Duracell Ultras (for gear you store between uses).
Oh, and don't bother trying to conduct your own battery of tests.