KMASHI 15000mAh MP836 (2Amp+1Amp Output) Dual USB Fast Charger Ultra-High Density External Battery PackKmashi via Amazon offers its 15000mAh Dual USB power bank for $19.99. But when you use the coupon code: Q29OJRQH the price drops to only $13.79 Prime shipped. That's $6.20 off the regular sale price, $1.21 less than our previous mention and the lowest we've seen. It has "a super-fast charge output (5V / 3A total) through dual USB ports (5V / 2A and 5V / 1A) allowing for simultaneous charging of your iPad, iPhone, Android, and more devices at high speed." It can supply 2X the life to any iPhone. Amazon shoppers gave it 4.3/5 stars.

Aukey 12000mAh Portable Power Bank

Aukey Direct via Amazon has a 12000mAh Portable Power Bank for $21.49. If you enter the code 24T62LQW at checkout, the price drops to $9.99 Prime shipped. That's $11.50 off the regular price and the lowest we can find it for. It completely charges up in 6-7 hours and has 4 blue LED indicators that let you know what the remaining power level is. It received 3.9/5 stars from Amazon shoppers. 

Also, Aukey has its 8000mAh power bank for $19.99. But if you enter the code: NBNRLJG3 the price drops to $8.99 Prime shipped Read more of this post