ayhan 
Ebay has Samsung 10,000 mAh Portable Battery on sale for $15.99.
10,000 mAh Portable Battery with USB-C Cable, Silver -Direct from Samsung
10,000 mAh capacity provides up to 2 full charges from 0-100% on most of the latest smartphones*. Fast charge Galaxy S9, Note9 and more at up to 15W power output.
