Can anyone shed any light on why my export is going beyond the 20% I Have set it to?

    Woz86 We calculate what the estimated end time should be based on kW discharge rate.

    If however you see big drops in SOC, more so than expected, this could be inaccurate and may need to issue recalibration.

    Other Giv users have seen similar behaviour.

    Alternatively, you break your export schedule up into two separate schedules with a 5 min gap or so in between and different SOC requirement conditions.

        admin has this changed recently? Because up until about last week (GivEnergy firmware update), the battery discharged down to the % asked for in the WW schedule.

            Woz86 Nothing has changed to that behaviour from our end, no. We calculate the estimated end time when your SOC target would be reached and if sooner than your end time you specify, we use the adjusted end time.

                So, this thread caught my attention for a number of reasons.

                @Woz86 a quick bit of mental arithmetic, based on your graph, suggests you have a 5kW Hybrid and 8.2kWh Gen2 battery?
                Maybe just double check here https://app.wonderwatt.com/settings and here https://app.wonderwatt.com/advanced to confirm your battery and inverter figures are correct.

                You'd probably be better off splitting you discharge in to 3 half hour slots, with the last one scheduled to end close to your overnight charging period, if you have one.
                I haven't forgotten about the cheat sheet I promised, honest.

                It doesn't appear that you had an SoC jump/drop (maybe a tiny bit near the end), as the discharge rate is constant and linear. You should probably ask GE why it didn't hold at 20%. It's clear the instruction was sent by WW and received by your inverter.

                The second thing that sparked my interest was...

                admin Nothing has changed to that behaviour from our end, no. We calculate the estimated end time when your SOC target would be reached and if sooner than your end time you specify, we use the adjusted end time.

                I wasn't aware of this, or maybe I was and had previously worked around it. Anyway, I tested it yesterday (amending a few of my normal schedules) to investigate the behaviour, thus...

                Normally, I'd have the "Stop at" much lower to guarantee a full half hour.

                This was the result of that and two subsequent schedules (min 80 stop 76, and min 75 stop 71)...

                As you can clearly see, the SoC at the start of each was comfortably above the min, and yet the half hour was still shortened, so it appears the WW calculation uses the "required" and "stop", whereas IMHO it would be better to use the actual SoC, assuming it's above "required", and "stop" to perform the calculation for any time/rate adjustment.

                My final point on this is that, having already shortened the end time, WW then send the reset instructions prior to this, further shortening the discharge period.

                Something to think about, maybe?

                    MrMessy As you can clearly see, the SoC at the start of each was comfortably above the min, and yet the half hour was still shortened, so it appears the WW calculation uses the "required" and "stop", whereas IMHO it would be better to use the actual SoC

                    Nope, we actually do use the SOC. In this first case, we used 90%. And here is the logic we apply:

                    Energy Change (kWh) = Battery Capacity (kWh) × (Percentage Change ÷ 100)
Time (hours) = Energy Change (kWh) ÷ Charging Rate (kWh)
Time (minutes) = Time (hours - in decimal) × 60

                    For your specific example (90% to 81%, 19 kWh battery, 3.6 kW charge rate):

                    Energy Change = 19 × (9 ÷ 100) = 19 × 0.09 = 1.71 kWh
Time (hours) = 1.71 ÷ 3.6 = 0.475 hours
Time (minutes) = 0.475 × 60 = 28.5 minutes (rounded down to 28 minutes)

                    Resulted in an adjusted end time of 15:38.