Do they?

I see people use Watts and Watt-hours and mix them interchangeably all the time. Even people who absolutely know better than to do that.

But the two units mean very different things, and either unit can be used to describe one aspect of a battery.

Best I can guess is batteries are rated by name plate power. And raw capacity is about 3-4 times that.

Wouldn't surprise me if there is a bunch of finkie dinkie technically driven accounting stuff around how fast and how deep a charge and discharge cycle they're willing to do vs price. Not to mention adding supply effects the price as well.