westfw:
"In Europe, 100 miles is a long distance. In America, 100 years is a long time."There are two sets of answers showing up. One assumes that the device needs power (at least enough for "standby") FOR 100 years, and the other assuming that the device will be completely inactive, and only needs power AFTER 100 years.
BTW, I don't know that modern semiconductors are expected to remain operational after 100 years. Diffusion of dopants might render PN junctions non-working, and insulating gates non-insulating...
Just being able to store battery power that can be used in 100 years seems unlikely. May I suggest a gold record if you want something that will last 100+ years as well as instructions on how to play it. NASA had this same problem to solve back during the Carter administration. Was sending a precious metal a good idea on Voyager? Maybe it's an advertisement? We have gold, this is where we are, come get it!
Tim