I have change to load one my 18650 using a loader Trust 001 and using a solar changer with inside battery of 2600 MA
Speaking few and badly the English, I prefer to give to you the images.
Also with an input of 9 Volts, the output in the Trust 001 are of 4,15 / 4,17 volts
I have tried to load an only battery 18650 to the time, with two batteries 18650 are not easy.
I have also tried with 2 batteries 16340 and it is possible.
The solar changer must be plans to 9 volts; out.