My TIPS for you.
1- NEVER EVER buy a Power Bank just because the price is very LOW compared to others.
2- Buy Power banks with WARRANTY which is trust that the product will be good.
3- Check the battery Details before buying and make sure that the battery has really good chemical contents as I have heard of BATTERY GETTING EXPLODED in some cases while charging
4-Check the User reviews on any site before you buy it.
5- Make sure you buy a good charger and some POWER BANKS with capacity of more than 10000 MAH needs 2 or greater Ampere charger to get charged easily.so watch out
6- Dont buy from China stores and make sure you buy the real products.
7-Do a trial run on the first day you buy it to check the defects.
8- dont keep charge in battery or powerbank if you DONT use your power bank for more than 50 DAYS it can damage the Capacity of a battery.
If you find my TIPS helpful.please like and RATE MY review.Please.it will suport me and make me do more honest reviews for you.
Thank you