Have been working with my new Goal Zero Yeti 400. The designation means the battery holds a 400W charge, how much you draw on that will depend on how long it lasts. The gauge is in 20% increments and it is recommended to never drain the battery, best not to go below 20%.
This morning, from a fully charged battery, ran an electric pump rated at 150w. Start up drew close to 200W, then settled down to +/- 150. After 34 minutes, charge was down to 60%. Took about 2 hours on a 100w solar panel in full sun to charge the battery. The panel was not directly aligned with the sun, but the angle was not seriously off.
Also used a 10W solar panel to charge my cell phone. Would have been much quicker off the GZ while on the panel without seriously effecting the charging time. think it was over 4 hours to charge the phone!
Now is the time to know how well these devices work!