RAVpower 120 watt charger RP-PC146 doesn't play nice with Framework 13

I have a RAVpower RP-PC146 which works properly with my other devices (phones, mice, Macbook Pro, Surface Pro, etc). With the Framework 13, however, it oscillates between charging and not-charging every couple of seconds. Sometimes that oscillation ends after 3-10 minutes. Whether it ends charging or not is non-deterministic.

I suspect that there is a mismatch between the negotiated contract and the drawn current, or that the laptop ramps up to maximum current faster than the charger is able to stay in regulation. I don’t yet have appropriate test equipment to analyze in detail what is going wrong.

In the mean time, consider this a PSA that this is an incompatible pairing of laptop and charger.

This seems to be the conclusion of other threads on here where people have chargers that don’t work with their FW.

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Is there a schematic of the charging circuit on the Framework 13 AMD? I’m interested to see if this might be fixable via firmware or a rework.

A firmware fix should be enough.

But schematics are on their github. With more available to repair shops, if they apply for it. Doesn’t look like the AMD board has been added yet.

If they’re still using the ISL9241 in the AMD version, it looks like there’s a ton of knobs to turn to try and improve compatibility. There’s one under-documented bit that enables a slew rate control on the VSYS target DAC channel.

It’s not obvious how the control loop selector selects its loop, and under what circumstances it’s regulating on which of its four measured parameters.

Looks like the slew bit is set on laptops which use this IC:

It appears that power connectivity oscillates more severely when the computer is on than when it is off. I wonder if the input current limit is applied differently in the two circumstances.