Q: I have a Samsung S8 which is fast charge capable. Why isn't your product fast charging my phone?
A: First of all, the battery pack is able and should fast charge your Galaxy S8. If fast charging is not happening, it is usually one of the following causes:
The last cause, #5, is normal behavior. You can compare by using your stock AC adapter to top off your phone's battery. #4 is known to happen with various phones. Sometimes, a factory reset or OS upgrade will mysteriously fix the problem. #3 is easy to rule out -- you can go into the settings of your phone to check if the battery setting has been enabled for fast charging.
To ascertain whether it is #1 or #2, I need your help to verify a couple of things. Could you please contact us at email@example.com? It's a relatively quick process. Meanwhile, please read Page 1 of the user guide to make sure that you do not incorrectly apply the charging mode (link to the user guide: https://zmiusa.com/docs/QB810user_guide). If the battery pack is defective, we can discuss your options for return/refund.
The bottom line: We strive for your 100% satisfaction. It's important to us. We're here to help (firstname.lastname@example.org). Thank you for choosing ZMI!