These are trash.
1 of 2 units had issues upon initial charge, was left plugged in overnight yet still did not indicate a full charge. After a rest period and a second charge attempt, both units indicated a full charge. Both units tested well in electronic devices and appeared to be fully functional.
These were then set on a shelf (cool, dry place) for 3 weeks and were completely dead when I was ready to try getting some actual use out of them. Charging LEDs still illuminate on both units when plugged into a power source, one indicates a full charge (green light), the other indicates active charging (red light). However neither will actually hold a charge. Tested with a multimeter and both batteries indicate less than half a volt available. While plugged into a charger they indicate 4.2 volts, so they have effectively become just step-down converters and will no longer store energy.
Yes, these lasted a total of 1 charge, but could not hold onto that charge while stored for 3 weeks. I am now just outside of the return window, so the reality of it is that I spent $10 to buy e-waste. Save your money and look elsewhere.