Just check coupons out (with price alert and history). Let’s see what best price is ATM.
Input Current: 0.6A max., Output Voltage: DC 1.48V, Input Voltage: AC 100~240V 50/60HZ, Charging Cell Qty: 4
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest price update (UTC time):
Price history and price alert
Price history (for all/most countries) for Beamday C4 Battery Charger is here.
Price records source(s): Gearbest
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)).