Battery ADC level  :

     ADC Value > D4 -- Both iRiver and Rockbox runs    
C8 < ADC Value < D4 -- iRiver firmware refuses to load but Rockbox works prefectly
     ADC Value < C8 -- Backlight blinks when ATA Hard Disk access (not good for the hardware i think )
     ADC Value < C0 -- iHP turns off instantly when ATA Hard Disk access