Thank you @amosbatto and @irvinewade
Btw. I am not sure that it is clear, that I am not meaning charging only, but also the total current that Librem 5 consumes. So this means running the device plus charging the battery.
So what I get until now is the following:
Librem 5 only accepts 5V at the moment.
There is evidence that Librem 5 consumes over 5V 2A.
There are statements (official?) that the battery can be charged at up to 5V 1,6A.
This would mean that everything that would be above would go for running the phone and as the phone needs different amount of power depending on the load this would explain the fluctuations up to 5V 2,5A
Now what I still don’t get is the following:
Librem 5 will negotiate with the docking station 5V.
Does this means that the docking station will have to negotiate 5V with the power supply as well or could the input and output voltages of the docking station be different?
Irvinewade writes that it will depend on the docking station itself but I have not found any evidence on the internet that the case exists in which the negotiated voltage for the input and output will be different. I don’t know also how do people interpret the “Pass Through” charging.
This question is very important for understanding because if the docking station does need to negotiate 5V with the power supply than a power supply like the 5V 2A / 20V 3,25V I have, would be total crap for convergence mode. The original power supply 5V 3A would also be insufficient for a great convergence experience. So one has to not only look for a proper docking station, but also for a proper power supply capable of something like 5V 5A or 5V 6A.
The world would have been too easy if there was an original Librem 5 docking station with power supply
Now I understand why many computer brands are able to sell docking stations for several hundred USD. 