Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
Coupon (20.32 USD): BGTorch4
(CouponsFromChina.com tip: apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): linepayflt, EYBG, BGBSKL, BGSS4, eybg, BGTORCH, 502C6B, BGBFCR41, bGhOnEy10, bgshOOp10, BgoFErTaSchInA10, BgcLuBofErtA10, BGFLS15, BGAFF10OFF, BGCuponation10, 4BLF, BG10OFFAFF, BGwhielabel, BG10OFFAFF1, BANGGOODSD
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for LiitoKala LII-S4 Battery Charger.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).