"At a fixed computing load, the amount of battery you need will fall by a factor of 2 every year and a half," coined by Dr. Jonathan Koomey in 2010. A year later, Koomey revised his prediction from 1.5 to 2.6 years.
Koomey vs. Moore
Both Koomey's law and Moore's law deal with chips. While Koomey's law deals with energy consumption, the more widely touted Moore's law refers to the number of transistors on a chip. See
laws and
Moore's law.