Let me see if I understand:
The top light goes red when you plug in the USB to charge the PCC.
And the bottom light never does anything at all.
Is that correct?
If so, that isn't how it should be operating.
When plugged into a USB, the top light should be red while charging, and green when it is finished charging.
When a battery is screwed into the PCC, the bottom light should be solid red while charging, and blinking slowly when it is finished charging.
Whether the PCC is open or closed while charging either itself or a battery doesn't matter.