I suspect that much of the drop is in the last few inches inside the kitchen cupboard and through the USB wiring! It took many goes to get an adequate USB power cable, and was one reason to downgrade from 3B+ to 3B, since the 3B peak draw is less I think. I do attempt to compute the values on the fly, like this:
Verbose mode ($Id: powermng.cpp 25520 2018-09-11 06:13:20Z dhd $).
Sleep before power measurement.
LOAD POWER (mW): 6977
SS-MPPT-15L Vb_f slow battery voltage (mV): 12778
SS-MPPT-15L Adc_il_f load current (mA): 546
Input flag DUMPING is set.
System dumping for 100m.
SS-MPPT-15L Adc_ic_f battery charge current (mA): 0
NET battery charge current (mA): -546
SS-MPPT-15L T_batt (C): 21, temperature compensation -15mV.
Estimated LA battery impedance: 83mohm.
Estimated LA battery sag/(-rise) from internal impedance, and nominal internal voltage, effective w/ temp comp: -45mV, 12823mV, 12838mV.
Estimated actual battery sag from load (mV): 45mV.
LA/B1 dynamic threshold adjustment for load current -45mV.
ADC command 6a 80
ADC (6a 0) response 1347 (5 43 0)
Battery voltage 1 local (LA) 12638mV.
Supply drop B1 to BV 140mV; implied supply impedance 256mohm.
Adc_vl_f load voltage (mV): 12778
Supply drop B1 to controller load terminals 0mV; implied controller impedance 0mohm.
Supply drop controller to BV 140mV; implied wiring impedance 256mohm.
Input flag EXTERNAL_BATTERY_NOTVHIGH is set.
Input flag EXTERNAL_BATTERY_NOTFULL is set.
Battery voltage 1 basic compensation -60mV.
Battery voltage 1 'very low' threshold 12200mV (raw 12200mV).
Flag EXTERNAL_BATTERY_NOTVLOW is set.
Flag EXTERNAL_BATTERY_VLOW is unset.
Battery voltage 1 'low' threshold 12390mV (raw 12450mV).
Flag EXTERNAL_BATTERY_LOW is unset.
Battery voltage 1 dump margin threshold 12390mV (B1 delta 150mV, sag for dump load 107mV).
Battery voltage 1 'not high' threshold 13405mV (raw 13450mV).
Flag EXTERNAL_BATTERY_NOTHIGH is set.
Flag EXTERNAL_BATTERY_HIGH is unset.
Battery voltage 1 'very high' raw threshold 13600mV.
Flag EXTERNAL_BATTERY_NOTVHIGH is set.
Flag EXTERNAL_BATTERY_VHIGH is unset.
Flag EXTERNAL_BATTERY_NOTFULL is set.
Flag EXTERNAL_BATTERY_FULL is unset.
Input flag FORECAST_PV_GEN_GOOD is unset.
Battery extra USoC reserve for poor forecast / VHIGH and FULL not recent 5%.
Battery 1 effective/usable SoC 100%, dump thresholds min 60% higher 80% (uncompensated USoC 100%).
Setting sampling_down_factor to 50.
Setting up_threshold to 60%.
Setting sampling_rate to 25000.
Input flag NODUMP is unset.
External flag file /rw/docs-public/www.hd.org/Damon/Env/_gridCarbonIntensityGB.red.flag is absent.
Input flag GBGRIDPEAK is unset.
Dumping driven by external factors.
Flag DUMPING is set.
Flag DUMPINGEND is unset.
LASTDATA: 2020/07/01T19:41:03Z AL 0 B1 12778 B2 -1 P 6977 BV 12638 ST OK D e A1P 0 B1T 21 UC 100
Glad you like the podcasts: you just doubled my audience. You can even be in one since I'm itching to test Zencastr for real!
And of course you can have an autograph, possibly on a check/cheque from my US checking account to give it some real value! B^>
Rgds
Damon