Inspired by many iPod USB batteries I've seen online and after seeing the small Sijosae Amps inside a 9V battery I designed and built this First Gen 9v battery adapter... the "moOSe v1". Named after 'Moose' my 6mo. old Choc Lab. http://www.headphoneamp.co.kr/ftp/sijosae/Gallery/
- view Sijosae's Designs
Originally I was assmebling Radio Shack pre-made battery packs (2xAA or 4xAA) in Altoid tins with USB (5V) connectors. However these AA cells were large & required both frequent battery changes, low voltages, required cables and had poor charge times for a dead iPod...problems.
See Ted's excellent reviews: http://home.speedfactory.net/tcashin/ipodbattery.htm
Firewire has better potential, smaller packages and requires no cables. Newer iPods only...
Using rechargeable NiMh 9 volt batteries provide higher voltages for use with firewire than AA's, although most have only 700mAh while the AA batteries can be obtained up to 1200-2700mAh. However AA Packs of 6 or 8 can be awkward, heavy and hard to manage easily. Alkaline 9v's can be had online or at discounts as low as 55 to 99 cents ea.!
So we use 9v in series or parallel with firewire!
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