It's been said that you can never be too young, too skinny, or too rich. A similar aphorism for smartphones might be, "they can never be too fast, too hi-res, or have too long a battery life." The user in search of longer untethered battery life has a few options including external packs or extended batteries for phones that support them. And today, Galaxy S5 owners get a new option in the form of Mophie's $99.95 Juice Pack.
The trend towards integrated, non-removable batteries has caused much weeping and gnashing of teeth among the Android faithful, and nowhere is it more passionate than from the Nexus crowd. If you've been lamenting the Nexus 4's lack of a removable battery, ZeroLemon (purveyors of ridiculously huge extended batteries for major phones) has something they'd like you to see.
That's an external battery case, a form factor famous for turning svelte, short-lived iPhones into hulking bricks of longevity.