i think the battery cost of websites and even apps is fairly well invisible to users. there's certainly facilities which say how much battery some app has used,

i think the battery cost of websites and even apps is fairly well invisible to users. there's certainly facilities which say how much battery some app has used, but if it's a frequently used app it's a tautology. users don't care because they can't. the can pick battery life when they buy their phone (at the expense of important features), but they cannot optimise at any time thereafter. most people who would care are rational and since they can't they don't therefore, it is browser and os developers who need to act to stop these costs being externalised. show current battery consumption rate for this app/page in the status bar. then, people will start complaining about dirty webpages