Get coupons, create price alert or check price history out! Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Output current 12V-40A/ 24V-20A, Input voltage 130V-250V, Color Silver, Input cable 110cm, Material Metal case, Charging current 40000mA, Size 180x145x70mm/7.1×5.7×2.8in, Applicable voltage DC 12V/24V, Scope of application Lead-acid battery / maintenance-free battery / dry battery water battery (non-rechargeable lithium battery), Rated power 400W, Model AJ-618A
Banggood
Banggood warehouse is located in Europe 
. Sorry, but there’s no price history in my database.
Link: Banggood product page
1. ($41.85): Cuponation9
2. ($41.85): 9OFFSUMMER
3. ($42.31): hoNEYbGdeAlS
4. ($43.23): BG00c906
put item in your cart and apply coupon code there 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): MVC8SPRING, 8BGwbg2204, 2203ActiesNL, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN
(there’s a little possibility that old coupon will work)
Price history and price alert
There is only one database record (it was for $37.99), so you can’t see price history chart.
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)).