Re: Whilst on this topic..
actually... battery life _IS_ a selling point for laptops, slabs, and even phones.
There are 2 factors to consider:
a) weight/size
b) capacity
You can have a lightweight laptop with lousy capacity. You can also have a laptop with a bozillian hours of operation, but it weighs a lot or is 3 times as thick because of all of the batteries. Then there's replaceable vs soldered-in batteries [a big problem nowadays with slabs and phones at least].
So if you can predict the number of charges on a battery BEFORE you install it, you can (literally) grade them and select "the best" to go in the higher end devices, etc.. and ALSO let people know when it's time to "buy a new one" for the cheap stuff and/or automatically adjust for a repaired device [new battery].
Anyway, this is how I see it. But I also expect that only very new designs will start using something like that, maybe as soon as a year or two from now. [there is a predictable time delay from innovation to implementation and finally getting out to market].