Portable iPod and phone chargers are by no means anything new
. However, there are two main aspects of portable chargers that I think could be improved without sacrificing any of their functionality. These are:
Aesthetics. There is nothing wrong with an Altoids tin, but there is also a lot of room for improvement as far as looks are concerned.
Batteries: The vast majority of DIY portable USB chargers use alkaline batteries, which means that they must be replaced when they run out. Also, their capacity is not especially impressive.
My goal was to fix both of these problems, while using only parts I had lying around. Every single component of this charger I either already had, or I pulled out of some broken electronic device. Because I only used what was available, the charging circuit uses a 7805 voltage regulator, meaning it is not especially efficient. On average, it will still be more efficient than a 9V charger, because the peak voltage of the Li-Ion battery pack is around 7.5-7.8V. Had I built a Mintyboost type circuit, it would no doubt have been more efficient. However, as the battery pack I used is significantly larger than AA batteries or a 9V (it is 1/3 of a 15" Macbook Pro battery, in fact), this device should be able to power any iPod, phone, or other USB powered device for hours at a time before it must be recharged.