I’m using Nordic PPK2 in source mode. The output voltage was 4.084V when I measured the 80uA/351uA currents. The capacitors are not parallel to a battery, they are only connected to the battery connector to smooth the current consumption while measuring with PPK2.
Active sleep PSM floor current: With the capacitors I see 27 spikes in a 100ms measurement window and the max current in this window is 1.50mA. Without the capacitors the max current is 19.97mA and the current is switching 48 times per 100ms window.
I’ve done the same measurement using Nordic Thingy91. Also with Thingy the current graph changes a lot in a 100ms window, but the avg current doesn’t change much. Avg is about 185uA. Max currents are 270uA/17.48mA with/without capacitors.
There may be some losses in the capacitors, but I don’t think they should be significant. My assumption is that the feather current is changing so much at a high frequency that the PPK2 doesn’t measure correctly.