Mine is labeled 26,800 mAh, both in the instructions and on the power bank. How is yours labeled?
You are getting about 9.6 watts charging your bank using your current setup. I charged mine using a Pixel phone charger with the Pixel supplied USB-C to USB-C cable and get 18.4 watts charging the bank. It maintains that through most of the charge cycle then tapers down to about 4W before termination.
I cant be sure if the charger is authentic and I would rate the build quality as average.
Were you able to crack yours open yet or measure capacity?
I made a mistake it’s labeled 26,800mAh just like yours. I haven’t been able to get one of the ends off yet, but still trying without damaging it. But I was able to recharge it fully using
a Knofarm 48 watt USB-C wall charger. The power bank required 107 watt hours of power to top off at almost 4 hours of charging.
MoKo Metal LED Desk Lamp with 5V 2.4A USB Charging Port, Rotatable Home Office Light with Stepless Brightness/CCT, Touch Control, Custom Light Mode, Memory Function, Timer