But even if you're not living in an off-grid solar setup, good power banks will come in handy. This obsession started when I (Scott) lived off-grid in a vintage RV, powered primarily by solar panels. To help, we've spent years working our way through all of them. There are hundreds of portable battery packs, and picking one can be confusing. But if you keep a battery-powered portable charger handy, all those situations are in the past. Portable devices have a Murphy’s law–like ability to run out of power at the least convenient moment: as you step on the bus, right in the middle of an important meeting, or just as you get comfortable on the couch and press Play.