Can we do better then that ? http://www.youtube.com/watch?v=TNTRLlHRH_M#t=137 (http://www.youtube.com/watch?v=TNTRLlHRH_M#t=137) ???
The answer is yes
Lots of ways
Calc ulator solar to charge AA battery then to jt to charge A battery 7ah to supply a joule ringer with led
Earth battery from piratelabs to supply leds
Recycle fuji flash camera from lidmotor see2 NILS CIRCUIT
All had been successfully uploaded in YouTube for free