We recently posted the 25000mAh model for $23.
In addition to the USB-C port, it has an 18W QC 3.0 USB-A port and 12W ismart USB-A port for simultaneous charging of up to 3 devices.
Prime members only. Amazon with Sunvalley Brands has the RAVPower RP-PC083 Qi Certified Wireless Charging Pad with "Sleep Friendly" LED Indicator with Micro USB Charging Cable (AC Adapter Not Included) for $6.99 - $2 off coupon (check "Save an extra" box) = $4.99 with free shipping.
Shell Shocker! Today only. Newegg with Sunvalley Brands has the RAVPower 20,000mAh USB Portable Charger Battery Pack with Dual iSmart 2.0 USB Ports (Black, RP-PB006) for $15 with free shipping. Up to 5V/2.4A output per port (total 5V/3.4A).