We have a bunch of different flavors of alkaline battery holders to suit your different needs, including waterproof varieties. Each battery adds another 1.5V to your total voltage. For most wearable projects, stick to 2 to 4 Alkaline or rechargeables for about 3 to 5 volts.
Alkaline packs are great-- the batteries are easily replaceable and the hard plastic keeps everything safe.
For easy charging, nothing beats a pack of Nickel-Metal-Hydride batteries. Three AA’s will power most projects, four AA’s will alleviate the voltage drop that occurs over long lengths of conductive textiles. However we also recommend avoiding long runs of thread in favor of soldering thin silicone-coated wire.
Projects you can build with a 3xAAA battery pack: