Input: DC 12V/24V, Output: DC 5V/1A, Version: English Version, Storage Temperature: -30℃ – 85℃, Work Temperature: 0℃ – 30℃, Waterproof and dustproof: IPx2, QC3.0: 5V 3A/9V 2A/12V 1.5A.
Go down and check coupons out. Remember to check price history if it is available. Do you want to know what the best price is?
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):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($11.03): BGCar1val
2. ($12.14): BgAuMotor
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/i1u
Old coupons (from the oldest to the newest): AM15prime, BGAnniversary, BG1111CAR
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Price history (for all/most countries) for Xiaomi 70Mai QC3.0 Car Charger is here. The lowest price was: $8.99.
Price records source(s): Gearbest, 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)).