Thank you for bringing this issue to our attention via the community. We appreciate all the replies/discussions followed up by @TechnicallyWell @joshuad11 @C4RB1N3.
Generally, it's recommended to charge the Anker PowerCore+26800 PD battery with a PD wall adapter as you know. To charge the PowerCore+26800 PD with a standard wall adapter(5V/1A or 5V/2A whatever), it will take much longer time to get it fully charged. As per our testing result, the charging current will be less or equal to 1A with the standard wall adapter due to the different charging technologies.
It is correct from what explained by @TechnicallyWell about the LED indicator showing status. As the consideration of enhancing the charging experience, the LED charging sequence on all Anker batteries is designed to be charging like a rugby ball shape, which means the first couple of LEDs will be charged quickly than the middle ones. And the last ones will be charged faster again to a full status.
To answer your three questions:
The PowerCore+26800 PD battery can be charged with a 1A or 2A wall adapter without damages as long as they are all in the good working condition.
Yes, it can be charged with a non-power delivery charger but it will take much longer time to charge it up.
We usually do not recommend charging the 26800mAh battery with a solar panel due to its big capacity, especially for the PD battery which requests more powerful power source. The power supply from the solar panel may not be consistent whereas the Anker 26800 takes a long time to charge even from a non-PD wall adapter due to its large capacity and the unqiue Power Delivery charging feature. When the charging is interrupted, you may have to reconnect the battery to let the charging start again which is a problem for solar charger since the power supply may be affected by the environment.
As you also ordered the PowerPort II PD wall charger, you can charge the PowerCore+26800 PD battery with it and see if it can be charged in around 4.5-5 hours. If any further issues, you can contact us via email@example.com and we will be more than happy to help you out as per the 18-month warranty policy.
Thanks again for being an Anker family. Have a great day!