That and batteries seem to recover slightly from short intermittent use. There is another factor of how the driver circuit acts though, and it's related to what subwoofer mentioned about some drivers not being able to reignite a light that's been shut off when the battery level is too low, even though it was running fine before it was shut off.
The problem is if there's a potential for the driver circuitry to draw more power at turn on than it takes to keep the light running, in which case, turning it on and off more frequently may possibly flatten the battery faster than if it was turned on and kept on for longer periods.
This is all moot anyway. From subwoofer's tests, it appears the lights can live up to their claims of running continuously for 120 days, in which case, using the lights for only 8 hours each day, it would run for a whole year on one battery! If you used it only for the typical 4-5 hours per night that most people do in power outages (they just go to bed earlier), it would potentially run for 2 years.
I don't know about anyone else, but if I'm stuck in some kind of last ditch situation where I'm so unprepared that I don't have any additional batteries or a way to charge the battery I DO have for even 120 days, much less a year, I think I'm probably screwed.
Max