Don't get any of those OVERPRICED JB3 batteries made by Creative. The JB3's run fine off anything external which pitches a 5V output. I have a couple options that work great. I use an adjustable external battery that is made to power digital cameras made by Digital Concepts. It is light, small (card deck) and does 3v, 4.5v, 5v, 6v, 6.5v, and 8.4v. It straps onto a belt and was purchased at a Fred Meyer which is a common retailer in the NW. It powers the JB3 for over 8 hours EASY and cost $30, tax-free. (Gotta love Oregon) There is also a back-up I bought off eBay it is longer and heavier so I only have it as a back up. It has a proprietary power cord but still throws out about 6 or 7 different DC voltages. Look around some and good luck.