Love these adorable lights.  We strung them around our canopy to give light in the evenings.  I am not sure exactly how long they run for, but I know they've still been lit up around 1-2am at various times since we've had them up so they definitely run plenty long enough to meet our needs.  We have 3 strings of these lights strung around our canopy frame and they are bright enough that we can play games at the table under our canopy with ease.