I use the new low self-discharge (LSD) rechargeables. The Sanyo Eneloops were the first, and they're great, just a bit more expensive. I liked the Sony Charger (can charge any combo of AAs and AAAs & a little faster than the charger Sanyo offers), so I got 4 Eneloops, 4 Sony CycleEnergys with their charger, and four Tenergy, a lower cost Chinese made version. The Eneloops are rated 2000mah and 1500 recharges. The CycleEnergys are rated 2100mah and 1000 recharges, and I forget what the Tenergys were rated, but it's close. There are also some 2700 mah batteries, but I think they're rated for 500 recharges. I get an average of four ~4 hour hunts out of mine, just rotate them. The low self discharge term means that unlike old rechargeables, they hold most of their charge for years (Eneloops hold 75% after 3 years). That's one purchase I guarantee you that you'll never regret! I got mine at Amazon, I'm sure eBay has similar deals. I can't tell the difference between the 3 brands so far.