title_body: How much of the power does the screen of e-Ink device consume? On Android smartphones, when you look into Power settings, it shows a neat usage graph, which usually looks like this (my phone has very similar #s right now):
  
  ================ 40%+  Screen
  
  ==== 10% OS
  
  ==== 8% System
  
  == Y% (Next largest program)
  
  
  Is there any similar data showing how much battery is eaten by the screen of e-Ink devices, as % of overall power consumption? 
  
  Clearly not ~40%, since the whole point of eInk is that it uses a lot less battery. But did anyone quantify it? Plenty of eInk devices run Android so the data ought to be there.
  
  
  
  UPDATE: To address clarifications requested:
  
  
  I'm mostly interested in the consumption of power during active reading. But I was greatly amazed to learn that eInk draws no power for displaying unchanging page, so that's a great answer even if unanticipated one :)
  Rate of page turning shouldn't be a major factor, since I'm only interested in % of consumption (unless device drains battery a lot when displaying a static page?). So any reasonable rate (2-4 pages a minute?) is OK
  Backlighting should be off or discounted, since I'm interested in eIink consumption, not backlight one. 
  I don't really care about make and model, mostly because for ballpark ranges they should all rate similarly - on smartphones, the screen usage of ~40% seems pretty consistent across devices/models. But we can take some standard eInk Kindle model if necessary to narrow things down; whichever one there's data for. 
  
  But an ideal answer would draw from a study across different eInk devices.
upvoted_answer: I beleive you are asking "can the power usage of an eink screen be quantified?"
  
  As long as you don't change the page/image it is not using anypower. 
  
  
    E Ink's technology is commonly referred to as "bistable". What does this mean? Bistable means that the image on an E Ink screen will be retained even when all power sources are removed. In practice, this means that the display is consuming power only when something is changing. For example, when reading on an eReader, power is only needed when turning to a new page but no power is consumed by the display while reading the page. - See more at: http://www.eink.com/technology.html
  
  
  To quantify a value for usage while reading you would need to define; 
  
  
  The make and model of your device
  If you are using device lighting and if so at what level
  The rate of page turning