Unifun via Amazon offers the Unifun 10,400mAh Waterproof Portable Battery Pack
, model no. U821, for $16.99. Coupon code "YDP2L5LC" drops it to $13.99
. Plus, Prime members bag free shipping
. (Non-members can spend $49 to bag free shipping; otherwise, it adds $6.74.) That's tied with our mention from last month and the lowest total price we could find by $6. It features a waterproof rating of IP66, dual USB outputs, LED flashlight, and LED power status indicator. Deal ends October 31.