Bryan - Read this from a review at AMAZON
"What you don't know is its power draw and that's a big deal to those of us living inside battery constraints. I have measured it and I'll share:
low: 15 Watts or 1.25 amps @ 12 VDC
medium: 27 Watts or 2.25 amps
high: 35 Watts or close to 3 amps"
Thats a pretty big power drain running high speed and you know it will be run all night long haha...
My 10-inch blade O2COOL fan will run full time a good two nights on one set of D-CELLS - I forget how many D-cells it uses - at least four each
NOTE: just checked my O2COOL for batteries. It has eight D-CELLS in it haha.. This is sounding like my tent camping days - we would carry a hugh action-packer box with us plum full of D-CELLS batteries haha.. Everything back then ran off of D-CELLS...
Roy ken