[lb1lf]

Ah, that figures. Mea culpa. In that case, a $20 power bank should provide at least a couple of full charges - but if you're anything like me, you'll forget to top it up at regular intervals and will find that its capacity is greatly reduced when you need it... :-/ (I cheat; I have a small diesel generator for use during outages - we're typically without utility power a couple of days every winter.

[douche]

Still, any solution based around a smartphone is going to be subpar, compared to the dirt-cheap FM receiver that can run for weeks or months on a couple of ubiquitous AA batteries.