Review on O2COOL 10-Inch Battery Operated Fan - Portable with Rechargeable Battery, Multiple Power Options - AC/DC Adapter, USB Port for Emergencies, Camping, Travel, Indoor & Outdoor Use (Orange) by Jesus Samaddar

This is my dream fan. I bought this because sometimes we sleep without electricity. Since I like to turn the fan on at night, I can charge it from the truck's DC outlet during the day. It will then run out all night, around 8am. I haven't tried turning it on at night from the built-in battery. I've also used it with D batteries. It's expensive, but it's good to have that option too. Also works great on the train. The adjustable fan blade is also good. I just have to remember to turn the switch back to off after charging. Very happy with this fan and I can get another one.