Editor's Notes & Price Research
Sunvalleytek via Amazon has RAVPower 10400mAh External Battery Pack for $19.99 - $6 w/ coupon code DMFVBX62 = $13.99.
Seems valid for both black or white color.
Shipping is free with prime or on orders $49.
Note that this same price went to frontpage a week or two ago, but that coupon code/deal expired. I don't know how to "unexpire" posts so I posted this one.