Input voltage Charger 5V 2A, Chargin time About 3-4h, Working current 1-5A, Power 50W, Battery capacity 6500mAh 11.1V, Working temperature -10℃-35℃, Size 150x70x40mm, Reachable pressure 140PSI(5bar/5kg/500kpa), Emergency lighting 80h, Maximum current ＜5A, Charging method Type-C, No-load current ＜2A.
Basically copy coupon, view price history or create e-mail price alert. What is best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG10OFFAFF1, BG4d9120
(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 BIKIGHT 140PSI Electric Pump 6500mAh. The lowest price was: $42.29.
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)).