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  • Growatt XH integration issues

admin I am thinking that the TLX not working different than other Growatt inverter , just that the menu set up seems different.(?)

So if I have a 9kW inverter , my max charge rate is 9kW . 50% is then indeed 50% of that max =4.5 kW ( the charge rate can be set in % or in kW directly in the app menu) .

So I guess the calculation you are doing today should work fine. Would understand you calculate the desired target charging SOC (%) based on current SOC, the battery capacity and solar forecast and the charge rate is simply the required kWh to be added ( based on battery capacity) divided by hours timeslot - expressed as percentage of max charging capacity?

So I would see the problem just as that you need to set the correct charging rate for TLX on the server. - which I think we noticed is not connected to any time period but a setting applying to all periods (and probably that you need to set the charging stop SOC and discharge stop SOC based on WW user settings) and maybe set them back to what they were before at end of charging

Sorry, not 100% sure we are saying the same things here or that I am on wrong track ?

      Jorrit Right, for now, we will expose the max battery charge rate in Advanced settings then, so you can change it. It's not straightforward to get that from the Growatt API - (though it is on Giv).

      Additionally, we will implement the stop charge and dynamic charge rate for Growatt TL-X.

      We will roll that out before doing the discharge changes, which we also want to sort out for Giv.

      Will keep you posted. @Jorrit @krustydad - please check the Release Notes and report your findings, thanks!

          admin Thank You for the "Max battery charge" field. Looking forward to see the effect. It will not be to night, though. Schedule says no need for charging:)
          Still believe it should be beside [Battery Capacity] in {Battery details] in the Setting menu. But that's a detail. Now it is there:-)

              perfrank No worries.

              Reason we didn’t want to stick it in Settings is because we can derive it from most systems, so it would add yet another field to that section.

                  admin OK.
                  This might be an old engineer's nitty-gritty. But should it be kW and not kWh? Effect, not energy?

                      admin There may be another issue. Schedule has just started and states 18% charge power. Growatt charges with 1.8 kW. This means that 100% is 10kW. And I entered 6.5kW in [Battery rate]. It seems as if WW does not care and still calculate with 10kW. With this charge rate, battery will be full in little over 3 hours , not counting for losses.

                          perfrank So this goes back to my question before. When you isssue a 50% charge rate on your inverter, what does your battery charge at?

                          I think your inverter charges at a percentage of its max rate and does not take into account the battery max charge.

                          Which is why my suggestion before was to introduce a separate inverter max charge as well in Advanced settings, so we can recalculate the correct percentage in accordance with your battery/inverter ratio.

                              admin
                              When charging 50% it charges with 5.02 kW.

                              5 kW is 50% of 10 kW, so inverter uses its max rate for percentage calculation.

                              I might have misunderstand how the calculation in WW works and why numbers come out as they do. What I want is that the calculated charge is distributed over the available periode. With upper numbers as example):
                              Battery capacity times (1 - SOC) divided by hours in period.
                              12.8 * (1-55/100) / 6 = 0.96 kW. Which is 9.6% of the 10kW. However, WW have calculated todays charge rate to 18%, which means, that charge has finished in 3.2 hours. I expected the charge to be distributed over all 6 hours. How can I achieve this?

                                  Status last night :
                                  Charge stop SOC 95%
                                  Charge rate 100%

                                  Status this morning::
                                  charge stop SOC : 100%
                                  charge rate at 100%

                                  I had put the battery max setting to 3kW , to give it a try.

                                  Looking at my import graph it seems charge at full 100% for about 30 min, but stop at the correct target level (it just hit SOC 74%)



                                  So SOC stop setting seems to work, but not charging rate

                                  So just to confirm: 50% charge rate is 50% of inverter power. I do not know if inverter may limit this by battery max rate for smaller batteries, not sure how I could check that .

                                  Note , at the end of the charge session can you set back the charge stop SOC and charge rate to what is was before the charge session ? Say WW charges it with 30% , in the afternoon I need it back to say 100 charge rate and my 95% default stop SOC to maximally charge via solar - ( I prefer 95% think better for batteries, but guess WW setting it back to what it was is always best option ?)

                                  Thanks

                                  perfrank

                                  5 kW is 50% of 10 kW, so inverter uses its max rate for percentage calculation.

                                  Cool, so now we know that, we also need the inverter max charge, as well as your battery max charge of 5-6kW.

                                  We'll add a setting for that (which we assumed we may have needed, so just as well we kept this under the Advanced section!).

                                  We basically need both (if they are different) in order to calculate the correct charge rate. If inverter charge rate isn't being set by the user, we just use the max charge rate of the battery.

                                      ok, I have notices something odd today...
                                      I have changed no advanced settings as far as I am aware (I did view them), and overnight charging correctly grid charging to 100%, but today the solar has pretty much stalled at 80%-ish and is exporting the majority.
                                      I cannot be sure if this is some oddity inside Growatt or the inverter, or if WW has set something...

                                      I know WW writes out to Time Slot 3, so not sure if the grid first is causing this?

                                        krustydad Ah, it might because with TL-X inverters you need a specific window/timeslot for Load First that should be enabled? @Jorrit ?

                                            admin It's been working fine until today, so not sure.

                                            UPDATE: it seems that Charge Stop SOC (seen above as 20%) was set by something.
                                            I have not knowingly changed this, but setting to 100% the battery has immediately started to charge from solar again.
                                            I cannot see anything in the WW log that makes me think this has been set, but is there anything not visible in the UI that could explain WW setting this?

                                            If it helps, I had looked at the Agile Octopus configuration page, and entered my postcode "to see what happened" but didn't save any changes as far as I know.

                                                krustydad

                                                So the question then is, did you Change Timeslot 3 back to Load First and also left it at disabled? And did that fix it?

                                                    Default is load first, so that would not need any timeslot. I think the thing we noted was in the timeslot you can only set the ‘mode’, nothing else . All other settings are general , ie apply all the time (and for all timeslots.)

                                                    Again , just to confirm I see the same on the server page : Timeslot 3 is left after WW charge with “grid first” with timesetting 00:00 - 00:01 and disabled .

                                                    (Guess you need to do like that as it seems you can not save back to default 00:00-00:00 . Will not accept that . So very messy time set up in Growatt it seems to me )

                                                    krustydad

                                                    UPDATE: it seems that Charge Stop SOC (seen above as 20%) was set by something.
                                                    I have not knowingly changed this, but setting to 100% the battery has immediately started to charge from solar again.

                                                    We do set both charge rate and charge SOC back to 100 at the end of the charge schedule. Those values are actually hardcoded at the moment.

                                                    From the logs I also couldn't spot anything to the contrary for your account. Charge rate and charge SOC stop got reset successfully.

                                                        krustydad
                                                        From Your screenshots I can see, that Your HX model is different from my SPH in the settings. On SPH, priority is set by enabling time slots in either "Grid first" or "Batteri first" group. Obvious not both can have an active timeslot. If neither is active at the actual time, SPH defaults to "Load first". I assume, that if all timeslot is "Disable", Your inverter should preferably do the same: Default to "Load first". If it does not, things get a little more complicated, and WW (or You) should set an enabled "Load first" slot.
                                                        I hope, that this makes sense. English is not my native language, and I struggle to make myself clear. And i miss a dictionary, with definitions, over PV related terms. Growatt could use that too;-)



                                                          admin Sounds fine.
                                                          When you get the time, I will very much like to have a description of the logic behind the Scheduled time slots with the calculation rules. Or is it very complicated? Or secret? It is just because I can better decisions entering parameters when I know the logic behind.

                                                            admin OK , checked it in a trial schedule. The schedules say charge to 37% with charge rate 43% . These settings are both correctly visible on the server and the time slot (3) is correctly set to grid first. We have already seen it will re-set back to 100% for SOC stop and charge rate after the session, so the integration works correctly

                                                            I also see it charging with 4.1 kW which seems in line with the 43% (9kW inverter)