beware heavy duty...trust alkaline

"Heavy Duty" batteries are a joke, IMO. Alkaline - though with Alkalines, "Heavy Duty" and "High Output" can mean something - or Lithium for disposables, NiMH for rechargeables are my choice. One thing to keep in mind about disposable batteries is that they have a shelf life. I suggest you buy 'em from places that sell lots and lots of the puppies. Those you find at convenience stores, pharmacies, and supermarkets have been on the shelf who knows how long. Those you find at major discount retailers, electronics stores, big home centers, and the like tend to be lots fresher.

I don't know how good the Radio Shack brand is, but geez, it's nice to need two batteries and be able to buy two batteries, instead of the normal six or even eight pack.

Radioshack batteries have generally given me pretty good service. They do sell a lot of 'em. and I've read theirs generally are among the freshest you can get. Dunno if thats real, but it would make sense. They do package 'em conveniently, and they carry just about every size and variety you might want.