Aliexpress
Click here… to search for Xiaomi ZMI QB810 10000mAh Power Bank Black on Aliexpress
Here are coupons that you can use.
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – Xiaomi ZMI QB810 10000mAh Power Bank White (-3 USD)
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (26.99 USD): BGXMI15
Coupon (26.99 USD): BGAFF10OFF
Coupon (26.99 USD): BgoFErTaSchInA10
(CouponsFromChina.com tip: put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): bankmi, 1wzmiw, zm810q, q810miz, zm1zq1, aff7off, e2bcea, 1zmibp, zm1w1mi, bgQB810, BGMIPOWER1, BG3CSUM, BGzmiw1b, bgssaff9, BWzmiw1e, BGaDmITAd, BGzmi1wg, BGZMI1w1, 0e7f33, FBCOUPON1, bgshOOp10, BgcLuBofErtA10, BG15POWERBANK, BGCuponation10, 13f142, BGHONEY2110
(you can check these old coupons out, but these probably won’t work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – Xiaomi ZMI QB810 10000mAh Power Bank White (-3 USD)
Price history and price alert
Price history (for all/most countries) for Xiaomi ZMI QB810 10000mAh Power Bank Black is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).