The Idea was to have an extra battery, which can be powered by many different energy sources. It should be highly energy efficient and shouldn't damage the connected devices.
It should be like this Multi-Charger, but maybe a little less complicated
![Confused :?](./images/smilies/icon_e_confused.gif)
I liked the Idea, to power things with a dynamo hub, since it doesn't use that much extra power to use it, and it's always available, no matter where you are.
I just ordered 12x AA 1,2V Ni-MH Betteries at ebay, which could be used for testing purposes. They are like These!
Tests with smaller batteries (AAA) had as a result, that the current was not high enough, to power a Laptop (ca. 2A and more). If that doesn't work, it should be usefull to extend the time the battery lasts.
For a high energy efficiency I'd like to use as little resistors as possible.
What do you think? Are there some heavy errors I didn't put in account? Do you think it's a usefull thing to have? One more original batterie is very expencive, so at least the price could be worth it.