Assuming it actually scaled like that, if the tablet had a battery life of 9 hours with 9000mAh and the phone had ??? hours at 3100mAh 5" at 16:9, screen area

Assuming it actually scaled like that, if the tablet had a battery life of 9 hours with 9000mAh and the phone had ??? hours at 3100mAh 5" at 16:9, screen area = 11.076.23 == 68.9661 cm^2 10" at 4:3, screen area = 15.2420.32 == 309.6768 cm^2 Rough battery life = 9 hours * (310/69) * (3100/9000) == ~14 hours. I guess this calculation is sort of meaningless though, given that it has assumed battery life ∝ (battery capacity/screen size), and that it has not factored in different pixel densities, display technologies, usage patterns, other hardware etc