Go down and check coupons out. Remember to check price history if it is available. Let’s see what best price is ATM.
Lifespan 3, Peak Current 500A, Capacity 13, Power Indicator Light Included(5 grades), Engine Starting Times 20~30 times, 19V/3.5A, 800mAh, Working Temperature -30℃~+70℃, 000 times, 12V/10A, Input 15V/1A, Weight 420g, 4~5h(5V/2A), Full Charging Time 2.5~3.5h(15V/1A), Start Current 250A, Brand CARKU(from Xiaomi Youpin), Material ABS, Protection 8 protections, Output 5V/2.1A, Size 160*75*28mm, LED Flash Light Included
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.
Link: Banggood product page
1. ($56.15): BGCARKU11
2. ($63.35): BgAuMotor
you should apply the coupon 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): BG249CAR, AM15prime, BGCar6699, BGCARKU138
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi CARKU Car Jump Starter 13800mAh.
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)).