I have taken a mi power bank 20000mah from market jan.2020 it gives best performance of fast charging my redmi note4 mobile almost 3 times I am charging my phone in a day as my phone has battery problem but mi power bank solves my problem .but it only one fault of not having flash light .sometimes I want to go out but I needs a light so I feels discomfortable as it has not any flash light.but the cost is to high.