I bought this product 3 month ago. mi products is a always best. mi power bank 2i 20000 mah’s battery backup is a very nice.this product is a very nice because I charged my mobile by mi power bank in one four times. this power banks battery life is very powerful. power banks battery backup is a very more. this power bank is a heavy. this powerbank is no heating in summer days. every person purchased it in my home. I like it.