Hello, I bought ambrane powerbank 10000mah in October, 2017 from flipkart for ₹; 700.
My experience with Ambrane is good. It charges my Asus Zenfone Max Pro M1 one and a half times.
Yes it has some negative points that it is heavier than li-polymer powerbanks and also it takes more than 12 hours hours to charge completely but what else you gonna expect at this price range.