I'm looking to have a graceful shutdown for my RPi so that it can perform for about 60 seconds after the mains power has discontinued. I've been looking around for weeks and have found 3 different options/concepts:
Option 1) - http://arduino.cc/forum/index.php/topic,70734.0.html - some type of supercapacitor solution to just give an extra minute or so
Option 2) - http://www.seeedstudio.com/depot/lipo-r ... p-992.html - I think this can be used to basically feed the usb in to usb out, and fall back on battery when usb in stops (but not entirely sure)
Option 3) - http://www.ebay.ie/itm/Rechargeable-Ext ... 3a7f2f0ddf - I'm not sure if devices like this can be plugged into mains while also supplying voltage.
Option 1 is ideal as the other 2 are more than needed. Failing that, Option 2, because I could house the board + battery with my pi. Just wondering if anybody has any thoughts/advice/experience on this. My head is whizzing trying to understand heavy electronics from other posts (its straining the cognitive abilities of a programmer). There are other forum entries about RPi and UPS and batteries etc. but nothing with a definitive solution.
Any help would be much appreciated.