The coupon price for E2145 4500mAh 28A 3.7V is 45.94 USD (in Banggood). Just check coupons out (with price alert and history). You probably want to know what is the best price?
Latest price update (UTC time):
Banggood (45.94 USD)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. The question is – is it a good price? From what I can see this price is higher than average price (31.00 USD).
Link: Banggood product page
Price: 45.94 USD
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): FIN5108, BG4X2145, BGwhielabel, 4BLF, BG10OFFAFF1, BGFLBA, BGdeals333, BGASTB, BGAlerabat15, BGtorch7, BGtorch2, BGAlerabatI, BGASTC, BGtorch9, BG8Alerabat, BGLED07, BGOutlight10, BGaa6062, FIN4108, BG132673, BG589b2e, BG8FORMULAMX, BGd57765
(I don’t think these’re gonna work, but you can try ’em out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – 4 pcs. Astrolux E2145 4500mAh 28A 3.7V 21700 Battery Unprotected [EU] (-3 USD)
Aliexpress
Click here… to search for 4 pcs. Astrolux E2145 4500mAh 28A 3.7V 21700 Battery Unprotected on Aliexpress
Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for 4 pcs. Astrolux E2145 4500mAh 28A 3.7V 21700 Battery Unprotected.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).