If it is a 1 A bias that would make a difference, yes. Can this be measured over the course of an hour? I assume the Amps-in value is on the CAN bus, so it could be recorded? If so, one could do an integration and match with the reported value?GregH wrote: Without calibration the difference of 1A over the course of a 5 hour charge at 8-9A can be rather large. We haven't found anything akin to a running Ah counter in the data so far.
How the car calculates the Ah capacity (or Gids for that matter) is not entirely understood... but it seems to be a mixture of Ah counting and voltage and temperature analysis..
 Actually I should amend that.. Doing a bunch of partial charges on the new car (say from 30% to 70% up and down) does introduce a drift in the SOC such that at lower voltages sometimes the car snaps down to the lower Gid/SOC over the course of a few minutes when it realizes it's off. I've seen this a few times and it's somewhat alarming. Now I pay more attention to voltage than Gids when I'm under LBW.
I think the poor sensor quality is no real hindrance to coulomb counting, if it does not introduce bias.