Mac vmware fusion with VM Micro OS

dear     all

as you know apple mac pro has battery power up to 7 hour because it's use OS of apple

we know that all other Laptop products can have up to 3 hour in standard battery because Microsoft OS take to much to run it

my  question is If I install vmware fusion on mac and create VM with  Microsoft OS, Is it will effect the battery of my mac laptop or not ??? can I use it up to 7 hour or up to 3 hour ??

thanks