The next generation rechargeables are pretty nice. They're referred to low self-discharge (LSD), as they will hold most of their charge (around 75%) for 3 years. I've switched over to them in my AT Pro and really like them, they also seem to last about half-again as long as name brand alkalines (there are different ratings, some are rated 2000mah and have a life expectancy of 1500 recharges, others are rated 2700mah with a life expectancy of 1000 recharges. If you're interested in them, take a look at the Sanyo Eneloop, Sony CycleEnergy and tthe affordable Chinese knock-offs, Tenergy. I got mine on Amazon (got some of each to test, can't tell the difference yet). I liked the Sony charger (4 discrete charging circuits, so you can charge any combo...), so I got it with 4 of their CycleEnergys. No perceptible performance hit on the machine that I can notice, I switch out when they get down to one bar.