Eneloop rechargeables (from Sanyo) are just like your average earth-trashing, disposable batteries—only they’re earth-friendly, wallet-friendly, and can be recharged up to 1,000 times.
It all has to do with, um, reduced internal resistance, reduced self-discharge rate, a new superlattice alloy… whatever, the science is pretty complicated, and we don’t have time to explain it to you (cough). The point is, they kind of last forever. And when they finally do die on you, they can be recycled hassle-free (other batteries have to go through hazardous chemicals removal first). Oh, and if an arctic hike is on your horizon, don’t forget your trusty eneloops; they’re fully functional at temperatures as low as -5 degrees Celsius. Pick up a 4-pack of AA or AAA eneloop rechargeables for only $14.99, at Wal-mart or Circuit City, or order online from Amazon.com or Nationalgeographic.com.