Pisen Electronics via Amazon offers Prime members the Pisen 10,000mAh Portable Charger Power Bank for $18.99. Coupon code "4QAH4W4O" cuts it to $12.34. With free shipping, that's a buck under our mention from two weeks ago, $7 off list, and the lowest price we could find. It features a dual USB output and includes a microUSB charge cable. Deal ends March 31.