How many tabs do you have open that you have not used in hours or even days? With the Tab Suspender you can expect a considerable reduction of memory and CPU usage and indirectly your battery consumption by automatically suspending the tabs you aren't using.
Is your browser loaded with 50+ open tabs, full of stuff you want to read later? Do not send them to the abyss of bookmarks. Mark & close them. Closetab will remember and help you with a weekly email digest to complete your reading list.