Effectively, here is how the new test feature works; but first let’s take a look at how Chrome uses resources like battery life. Like so many other web browsers, Chrome will idle background tabs. When idling, these background tabs require less active CPU time, and that means they use less battery life. In Chrome, any background page idles with the CPU load throttled after five background minutes; and this could be a new tab in the same window or a new window where none of the opened tabs are in focus (or actively in use). When in that state, these tabs/pages will “wake up” only one time every minute to check for any activity.
Google is proposing, instead, to throttle each page’s CPU load after only ten background seconds, not every five minutes. A Chrome feature page describes that this simple shift is expected to extend laptop battery life.