Support for the HTML5 Battery Status API is limited (Firefox and Chrome). See this recent tutorial on SitePoint. http://www.sitepoint.com/html5-battery-status-api/
Here's another article from SitePoint re: the Network Information API. That also has limited support (Firefox and Chrome). http://www.sitepoint.com/use-network-information-api-improve-responsive-websites/
I am unaware of any accurate, cross-browser method to determine processor/hardware information via JavaScript.