I have looked at those CSV files.
The 60W uses an adp (Adapter or Charger) input current limit of 2700mA, that equates to about 52W. So, it will only ever try to take 52W from the 60W charger. I don’t know why that is not set at 60W.
The 100W uses an adp input current limit of 4800mA, that equates to about 88W. So, it will only ever try to take 88W from the 100W charger. Again, I don’t know why that is.
The EC firmware seems to choose this input current limit, purposely below what the charger can deliver.
When it hits this input current limit, it switches to also pull from the battery.
There are also spots where it tries to recharge the battery again.
So, one could conclude that this is all normal behavior.
I would have thought that setting the current limits to 100% of what the charger can do, and setting VsysMax = Battery Desired voltage would cause more of a power buffer, thus not dipping into the battery so much.
One can prevent it charging by setting the user_charge_limit = 0 with an EC command, but the EC Firmware might need a fix in that area, so that if it see user_charge_limit == 0, it never switches to a charge mode, and stays in PSU + Battery top-up mode.
The user can set “user_charge_limit = 10000” to allow charging again. 10000 just be some arbitrary figure that will always be too high, so will never trigger and allow the normal automatic battery controlled charge limits to apply.
As observed, there is a definite benefit in using a 100W charger on the FW13, so that it uses the battery less during normal operations as the 100W charger can absorb more of the current draw peaks from the CPU. The 100W csv shows one instance of the CPU drawing 4529mA, 87W so that triggers a battery discharge for a short time. So this proves the CPU can draw far more than the cpu budget of 54W, for very short instances.
The FW13 cannot use a charger more than 100W. If you use a 180W charger with the FW13, it will limit it to only ever use 100W of it (20V, 5A profile)
The CPU PMF settings could be adjusted by the user so that it never hits the adp input current limits at the expense of lower performance.
So, in conclusion, I think we understand the behavior of the CPU and EC firmware a lot better now.