Like most things, the title of “best iPhone 6 battery case” is subject to change whenever something new and great shows up to challenge existing options, and as the iPhone 6 is still young, we’re expecting a lot of jockeying for position over the next few months. The latest real contender comes from iBattz, maker of some of the best iPhone battery cases I’ve tested. Refuel Invictus for iPhone 6 ($100, aka Mojo Refuel Invictus) is the first iPhone 6 case to include a great feature from some earlier iPhone 4/4S and 5/5s cases: removable, replaceable batteries.
Using solely the items in its own box, Refuel Invictus delivered the largest recharge I’ve seen yet for the iPhone 6: 127%, or a full recharge plus an additional 27%. That might be enough to justify the asking price for some people. But you can also add a second battery and external USB charger for $25-$30 more. If you’ve been hunting for a slim battery case that can keep your iPhone running endlessly, this might be the most cost-effective way to do it.