Walmart will be offering this onn. WIA20B100008835 Dual-Port Portable Battery Powerbank for only $13 (reg. $29.88). You save 56% off the retail price for this portable charger during the 2020 Walmart Black Friday sale (11/14-11/15). Plus, this item ships free when you spend $35+. The onn. Portable Battery Powerbank features a 20000 mAh capacity, dual-port charge, and digital charging indicator. Sales tax is charged in most states. Deal expires November 15, 2020.