If you are heavy smartphone users and you travels a lot then you should definitely have this because in human food is necessary likewise for charge is food a smartphone which produce charge for smartphones.
So it is a very essential accessory for a smartphone.
While you are buying a Power bank you should keep eyes on following things.
First you should make sure about your battery capacity of your smartphone, because you have to but a Power bank according to your smartphone’s battery capacity.
Then you have to buy a genuine product whether you are buying from offline market or online market, because there are so many duplicate products are available in market.
So, you have to search about the product and also about power banks.
Then you have to search for best offers for that product which you want to buy.
There are many Ecommerce sites which are selling power banks, so you can find a Power bank according to your requirements.
There are many companies like MI, Lenovo, Syska and many more which are producing a good quality product, so you can buy from them.
Atlast don’t buy a Power bank from Facebook advertisement because one of my friends was wasted money on these type of advertisements.