

Why not just use the stored charge multiplied by the average cell discharge voltage at max load for Watt-hours? This may even encourage them not to go overboard on max load ratings.
Sure it could be a bit higher than what the user gets after voltage conversion, but if they are not maxing it they may get better?
I’m no electrical engineer, so this question isn’t actually rhetorical - I’m wondering if this would work.
I suppose in about 4.5 billion years the Andromedans can start committing also. (That or nobody can since it won’t be the Milky Way any more)