Normal alkaline AAs are fine for the casual shooter, but in the long run, you’ll save money with rechargeables. Duracell and Energizer are good, but my favorite is Tenergy (sold at all-battery.com), which are cheaper and have worked well for me. Get a charger that is “smart,” in that it doesn’t stop just on a timer. I like the Duracell CEF90NC 30 Minute Charger, though I have an older version. Mine doesn’t take long (one hour), has built-in cooling, stops based on some sort of charging detection system that works well, and has worked without fail for 2+ years. The new model should do the same, unless they’ve messed things up. Then, you won’t have to change batteries often, unless your camera is particularly power-hungry. The charger runs $30 and comes with 4 Duracell batteries. Avoid 15 minute or faster chargers, as they stress your batteries more, are prone to overheating, and cost more.
When I got my first digital camera, I bought a charger with four AA batteries for $10. The charger took 16 hours, and would not stop automatically. It was inevitable; I charged the batteries for 24 hours once, but fortunately there was no apparent damage, likely because the charger is less apt to damage batteries for being so under-powered. One month later, one of the batteries leaked acid. If it had been in the camera, it would have corroded the contacts and perhaps render it unusable. I bought new batteries, but continued using the original three for my CD player. Another month later, I opened the player to find that the battery had leaked, and the acid had burned through the compartment, onto the CD, corroding it so that it was unusable. It was a CD I burned, but if it had been a commercial release it may have been a loss of up to $20. I stopped using those batteries, filed down the corroded part in the player so that the CD wouldn’t touch it while spinning, and used aluminum foil to fit the battery against the corroded spring. After several months, it became such a hassle to keep the aluminum foil in place that I stopped using the player; the batteries would frequently fall out of place despite my efforts. I paid $33 for that CD player; this was three years ago, and it was one of those fancy models that would play MP3 files from CDs (flash memory was expensive back then), so it was quite disappointing to lose.
That is my cautionary tale: be careful of the batteries you choose; the cheesiest option isn’t the best. Digital photography is expensive, but this is no place to skimp, as your camera is useless without working batteries.
In the banner, the chargers, from left to right: Tenergy V-2833, Duracell CEF80N, Energizer CHDC, Digital Concepts CH-1800. The Duracell CEF80N is the one I’m saying good things about above; the Digital Concepts CH-1800 is the one I’m saying bad things about. The Energizer one uses an 8-hour timer, so I don’t like it. I haven’t opened the Tenergy one, but it says it takes 18 hours, which is too long. The batteries on the left are Rayovac Hybrid brand, which are low self-discharge batteries. I’ve kept them for a year without charging and they still work, but I only recommend them if you use your camera infrequently, as they’re pricier. The middle ones are Tenergy brand, which I like. The Energizer brand batteries on the right are good too, but are $10 a pack.
If you don’t want to worry about changing batteries, or want some spares to keep in your bag just in case, lithium AAs are a good choice.