Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): 19BWS5, 24bws, FWC4S5, 20MWC, 502C6B, 12blitzw, BGBWC4, BGss10%bw, AFfbG10, BgcLuBofErtA10, BG20CHARGER, 10%ForNewBW, BGMBCBLE, BGAFF10OFF, BGCuponation10, 10%ForBGBW, BGHONEY2110, 13f142, BANGGOODSD
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for BlitzWolf BW-FWC4 + BW-S5 Chargers is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).