I have a small bilge pump connected directly to a 12V battery. The battery is kept charged with BlueSolar 75/15 and a couple of summer months-worth of data shows regular charge cycles on most days -- the battery spending most of a cycle in float. On those typical days, the yield is reported usually as either 0Wh or 10Wh when there's no other load usage. On non-typical days the yield reported will be higher, but it's always a multiple of 10.
I realize that the actual bilge pump consumption is not calculated by the BlueSolar device since it's not connected to the load port. Based on observation I know the pump runs for a short time every day.
Even on the days when the yield is reported as "zero", the MPPT reports time in each the various charging states converting energy and topping up the battery, so I assume that what is reported as "0" yield, is a small number of Whr, rounded down. Is this assumption correct? Can a more precise number be determined when the yield is close to zero?