If a blender has a power of 800 watts, what does that mean? Doesn't the power output depend on the torque or speed of the motor, which depends on what you're blending? A motor that is spinning freely should have no power output (assume superconducting wires), because there is no torque in a freely spinning motor and hence no current through the battery! A stalled motor also delivers no power output, although a lot of power is burned at the internal source resistance. Whenever a wattage is specified for a motor, doesn't there need to be a torque or speed specified for that wattage? Also, what exactly are the design parameters for a blender? It seems you'd want low wire resistance R, so that the start-up torque (the maximum possible torque) is huge V2/R so that you can crush ice. But isn't that all there is? If you can't get R low, then you have to use gears. But what else is there to consider?