ZeroLemon 8,500 mAh Battery Case
ZeroLemon is known for making battery cases, and they have one of the biggest we've seen yet for the Galaxy S7 Edge. This durable TPU and polycarbonate hard-shell case completely protects the phone, but then adds an extra 8,500 mAh of battery. As a comparison the Galaxy S7 Edge is 3,600 mAh so this case is more than double. Meaning users can go 2-3 days on a single charge.
The ZeroLemon case will charge your phone and can even recharge other devices with its huge built-in battery. The only downside is it's almost as big as a brick. Look at the picture, then decide if you'll be able to carry that around and if it's worth the $64.99 price.