This is AnkerDirect customer service. Thanks for letting us know the issue with your PowerCore + 26800 battery. We have located your contact to our support email as well. Could you please check your email box for more details?
Meanwhile, would you please kindly check some troubleshooting methods as mentioned by @ndalby @nigelhealy and @Jesse_Hernandez1? Thanks for all your kind suggestions.
FYI, the problem might be with the wall outlet, wall charger, cable or the battery. To verify whether the issue is with the battery, we just need to confirm whether the wall outlet, wall charger, and the cable are working well.
Should there be more concerns or questions, please feel free to reach us via "firstname.lastname@example.org".