Many IoT concepts are remote or battery-powered. Most of the single-board computers on the market will drain a 9V battery in a couple of days.
Wireless power transmission will be the enabler that causes IoT to really advance.
Wireless power transmission will be the enabler that causes IoT to really advance.
I'm not sure about that. If it's a stationary, long-term thing, just tap the main power conduit on whatever device you're hacking.
If it's mobile or short-term, Li-Ion cells are pretty awesome. For a few bucks, you could buy a Li-Ion cell, and a smart charger that will switch the load between battery and main power depending on voltage levels.