Thank you for bringing this issue to our attention via the community.
We regret to know that you have problems with the two Power Banks. Please accept our sincere apologies for the unpleasant experience brought to you. Rest assured that Anker always keeps to improve the product quality and take the full responsibility for the function of our products according to the 18-month warranty policy. Although we work hard to ensure high-quality standards through multiple quality checks, we regrettably still come across defective products occasionally.
Since the units have been returned for a refund, it's a pity that we are unable to try some troubleshooting tips to see if it can be fixed. In the future, we recommend you email us at firstname.lastname@example.org with your order details for support. We will be more than happy to help you out.
Sorry again for the inconvenience caused and thanks for your support.