Basically copy coupon, view price history or create e-mail price alert. What is best price?
22650, Calibration: Factory calibration, Discharge current range: 0.1A-1.5A, discharge, 17650, Input power: DC 12-24V/2.5A, activation, Voltage measuremnet: ±10mV internal resolution, 20650, Operating voltage range: 0.2V-5.0V/slot, Temperature sensors: 5 for inner, storage, Display: 320×240 IPS LCD, max.discharge power 10W, Standby current drain: <0.05mA/battery, AA, cylindrical, analysis, 18650, Cycle count: 1-66 cycles, 13500, 10500, 13650, External ports: DC input, Current measuremnet: ±10mV internal resolution, 14650, cycle, Battery chemistry range: 0.1A-3.0A/slot, 10440, Micro USB link, Operation modes: Charge, Circuit power: max.charge power 25W, USB power output: DC 5V/2.1A, Battery count: 1-4 single cells, 16650, 12500, Beep sound: Multi-tone, Operating temperature: 0°C-40°C, 14500, 26650, USB power output, Battery size: AAA
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
1. ($53.99): BGCITYADS2019
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): ISDTC4, 502C6B, rcmus19, PU15
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for ISDT C4 8A Battery Charger With 4x 2000mAh AA Battery.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).