Daniel Mauswrote a review of Goal Zero Yeti 400 Solar Generator on January 12, 2019
Familiarity: I've used it once or twice and have initial impressions
I got to test one of these out on my most recent week long adventure. I was surprised with how long the battery lasted and how often I used it. You get tons of output options so you can charge multiple devices at a time no matter the plug you have for each device.
I used it for charging our phones, gopros, laptops, and lights. It helped tremendously when we were away from any power source for days on end but needed to keep our cameras charged to get the content we needed! Another awesome feature is the display on the battery that shows you exactly how much juice you have left, which is nice to prioritize the charging of certain devices over others when you are getting low on battery.
The only gripe is the weight, however it's not terrible to carry around. They came out with a Lithium version which is about 10lbs lighter :)