Special offer for Gear readers: Get a 1-year subscription to WIRED for $5 ($25 off). Updated January 2023: We added new options from Otterbox, UAG, and RapidX, removed discontinued devices, and updated prices. Even if you're not living in an off-grid solar setup, good power banks will come in handy.

I had a proper 12-volt battery bank in the bus, but since I was out and about much of the time, portable power was more flexible and let me take energy where I needed it rather than having to be beside a plug. That experience taught me that the key to solar power is good batteries. 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 out there, and picking one can be confusing.

If you keep a battery-powered portable charger handy, all those situations are a thing of 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.

Pocket phone