I read it again and it appears you answered it there. However there are reviews where they cover runtime on battery power which is not to be confused with battery life span (cycles, months till you need a new battery.)
In fact you have to wonder if folk understand how costly it is to use the battery. Let's take the usual laptop with a 300 cycle battery. The maker's definition of wear out is 50% capacity (owners usually gripe at about 80.)
If someone used the battery exclusively, charged it daily they might need a new battery every year to keep the hours up to near when the battery is new.
Are you aware of this?