Anker 20100 charger

Purchased the above about a 18 months ago. It charged up fine first time without using Anker wall charger. A now it won’t charge beyond 1 blinking green light. I just purchased specific Anker wall charger. It’s been charging for 2 days, it still just 1 blinking green light. Any thoughts as to what’s wrong with it?

Believe you are talking about Anker PowerCore 20100. please mention which charger are you using to charge the PowerCore 20100. For recharging this powercore, it requires an Input of 5V @2A

the wall charger you are using needs to provide 5V @2A , else the PowerCore 20100 will take longer time to charge or may not recharge fully.

please provide the make / model of the wall charger you are using to charge.

Green lights on most anker baterypacks means it’s in trickle charge mode for output. I have never seen one that shows a green light when charging. As stated by @Shenoy what is the exact model batterypack your referring to?