On the MATE-3 when using the Grid Use mode, if the batteries are not at 100% SOC when the grid transitions from DROP to USE during an Interval, the charger will automatically top off the batteries to 100% SOC. Sometimes there is still Sunlight available to top off the batteries after this transition takes place. Suggestion: set a programmable time that the charger will begin its top-off cycle after the Grid Use Interval goes into USE so that whatever Sunlight is available can contribute to the SOC and the charger will only charge well after dark. By doing this, there will be times when the charger does not have to do any work because residual free evening light may top off the last few percent. Another reason for this is were I to manually switch from Grid DROP to Grid USE for a period of time (say, during a thunder storm), the charger will NOT automatically come on.