I apologize for the delay in response. The dim screen does not affect the battery benchmark - it just depends on your preference, as the screen will be on for the duration of the test. It is recommended (and the expected behaviour is a notification to the user to charge to 100%) to run the full discharge battery benchmark starting with a full charge. The only requirement to start a partial discharge battery benchmark is to have a charge at 50% or more. There is no required battery level to run the CPU or Compute benchmarks.