Most solar chargers are either gimmicks that would struggle to juice up a lemon, or giant packs you need a car to haul around. Goal Zero’s new Nomad 7 Plus looks like it might be the holy grail – small, cheap, and useful.

The solar panel can charge smartphones and other USB-powered devices in unpredictable environments without the aid of a battery.

The biggest difference between Nomad 7 Plus solar panel and others is hidden in a small modulator called the Maximum Power Point Tracking controller.

The controller helps optimize the output from the solar panels for the battery being charged, particularly given variances due to light and shadow encountered during charging.

It tracks the history of the power flow, so it understands if a device disconnects due to being fully charged or due to a lack of power (because of shade). It then automatically reconnects if needed.