Sunvalley Brands via Amazon offers its RavPower 10,000mAh USB Type-C Ultra-Slim Portable Battery Pack in Black for $25.99. Coupon code "DELPB078" cuts that to $19.49. With free shipping, that's $6 off and the lowest price we could find. It has one USB Type-C output and one USB Type-A output. Deal ends April 30.