Apparently not. From http://www.goalzero.com/de...:

Modified sine wave voltage inverters, like the ones used in the Yeti 150, are the most common inverters on the market. They work great with small electronics, usually anything that comes with an AC power cable, such as your laptop.

Some or all of the following devices are not suitable for use in conjunction with a modified sine wave voltage inverter and should not be used with the Yeti 150. Such use is solely at the owner's risk and Goal Zero assumes no responsibility for any damage or injury caused by such use. Fluorescent lamps with dimmer function, electrical tools using thyristor energy or variable speed control, digital clocks with radios, and sewing machines with speed control.

I had already suspected that. I have a power bank with 230V output. If you look at it with the oscilloscope, you see square-wave pulses that are made up of individual pulses. It's a problem with some power supplies because the PFC stage can't cope with it.