Casessary via Amazon offers its Casessary Samsung Galaxy S8 4,500mAh Battery Case for $32.99. Coupon code "20DEALNE60" drops it to $26.39. With free shipping, that's $4 under our mention from a month ago, a current best by $24, and the lowest price we've seen. It's compatible with Qualcomm Quick Charge 3.0 devices. Deal ends April 16.