Instructables is providing
full details on how to roll your own USB battery charger. The project, named MintyBoost, draws power from standard AA batteries cleverly concealed inside an Altoid container (from whence the name comes). Though it does require some know-how, including soldering, it promises to be accessible to those who’ve never dabbled in DIY before.
The resulting battery pack can provide an additional full charge to a video iPod, and several hours of charge to iPod shuffles and minis. For the technically inclined, this may be a perfect solution.