KMAX-808 7800mAh Outdoor Travel Flashlight Battery Pack Power Bank Charger for $9.99. Shipping is free on orders over $35. If needed, use this Filler Tool to pad the order for free shipping. Here is a screenshot for your reference. It has a rather high energy capacity of 7800mAh and is made by 3 x 18650 lithium cells. At the time of this post, there are 2 customer reviews, both of which have given it full 5/5 stars.