JayMardern

This has been working great thank you - you're right, it was just auth, the rest stayed as-is. I honestly don't mind the cloud reliance as long as it's reliable (it actually has been for the last few months after their infrastructure move) and it doesn't change (like it did in this case). My understanding is that the revised auth process was to improve security - which is fine but only if we know in advance it's coming.

Looks like the whole SunSynk API is down? Authentication no longer succeeding across the board. Any official announcements?

At night we simulate powering-essentials-only-from-battery by specifying 700w (our average essentials load amount) in the time-of-use 'Power' column. That slot also has a 50% SOC target: so at night, the battery is allowed to slowly discharge down to 50%, with a maximum draw of 700w. If a geyser (or other high-power item) gets powered on at night, the balance above 700w simply comes from the grid. This achieves what @Sidewinder mentions above in terms of allowing us to gradually drop down to a battery SOC 'checkpoint' so that there's always left-over-battery for an unexpected outage. (The next slot - until just before sunrise - is set to 30%, again with a 700w battery limit). This also ensures that we consume most of the energy in the battery (which hopefully came from sunshine the day before) - and also makes battery capacity available for spare sunshine the next day; whilst also going easier on the battery (low-ish current drawn over a longer time).

Yeah you can: battery charging doesn't contribute to load, so indeed you can have 4kW going into the batteries while the UPS/load port draws 3kW; the total power into the inverter (from, say, grid) would be 7kW.

@Madone69 could do what we've done and put the heavy loads on the Deye/Sunsynk's Aux port, whilst specifying a minimum Aux battery SOC % - which will keep other essentials running but cut Aux loads if battery drops below the Aux threshold. You can also choose to keep Aux running (regardless of SOC) if grid is up. This protects battery SOC% whilst keeping Aux running during grid outages... saved us from cold showers when the grid's gone down, more than once!

Depends on system size, When I started with a single 5kW unit, geysers/pool pumps/stove remained on non-essentials and were back-fed with Solar by the inverter's ability to zero-export-to-CT through the grid port: this meant I didn't need to worry about the capacity constraints of the inverter since if we exceeded it's limits/production, the balance simply came from the grid. Keeping these non-essentials fed by excess PV like this was critical for return-on-investment on the system, since they're a typical home's biggest power hogs. When we parallel'ed our second unit, we then moved all these non-essentials onto the inverter's Auxiliary port (which is still constrained by the inverter's UPS/load capacity - albeit now double thanks to the second one), to let them run if there's spare battery and/or PV when the grid is down. In retrospect, with our single 5kW we could've probably swapped the one geyser's element down to 2kW and then been OK moving just that geyser to the essentials/aux, for coverage during extended grid-outages; at the cost of slower water heating due to the smaller element. The other possibility is you can put 'non-essentials' onto change-over switches to swap them between non-essentials (for most of the time when you don't want to be bothered by limits) and essentials (when the grid goes down and you need hot water!) for a best-of-both-worlds approach if you don't have tons of spare inverter capacity.

Yeah, I've spent time with hardware from both Deye (colleagues) and Sunsynk (my own) and functionality is the same on-inverter, the only difference is terminology in the menus. And colour scheme! 🙂 My installer mentioned he preferred the Sunsynk app to the Deye solution when he did the second-half of my installation last year; especially with regards to modifying settings from the SS app. Maybe this has changed since, though. Sunsynk also has a nice API which is quite clean and well documented. But indeed, if none of that matters (or you're going Home Assistant or the like) I'd just go for whatever is cheaper at the time. It's not that bad: like Bobster mentioned, 5kW goes further than you think as long as you keep cooking and heating under control. Our household ran 5kW for about a year before adding a second unit in parallel; and we had no idea when there was load shedding unless we needed the stove/oven. And while 5kW limited what high-power items could be done on the UPS side, there's of course no limit on what you do grid-side (ie, on the non-backed-up side) - so if you keep your loads under control, you can still zero-export-to-CT to your non-essentials; since both the Sunsynk and Deye models discussed here can zero-export to the grid port. So even though my geysers weren't on the UPS side, they still got mostly heated from PV when sunshine was available. And when loads exceeded 5kW, the balance just came from grid. So the cost savings were impressive - very impressive - from just the one 5kW unit, mainly thanks to zero-export-to-CT. And load shedding was a non-issue. I might've considered moving the smaller geyser onto the UPS side (with a heating element downgrade to 2kW) if I'd stuck with a single inverter. But in the end we doubled the solar-panel-count and and needed the MPPTs of a second inverter. And with the second unit, all our high-power items could go onto the inverter's Aux port since the backed-up load maximum was now 10kW.

Most welcome, This is indeed unnecessarily cycling the battery: if you need 80% in the morning then why not just swap the 65% timeslots to instead be 80% and leave it at 80%? Dropping lower (and charging afterwards) might make sense if you pay less for electricity at that time though (i.e., if you're on a time-of-use tariff). I've found that even on rainy days we can usually keep the essentials going for our setup (our essential-load during the day is ~650W - less than 10% of our PV capacity), so I leave a reserve of just 30% for morning since even rainy days typically produce more than that. Then if there's LS, the combination of whatever PV's available coupled with that 3kWh of battery storage is OK, even for a 4-hour outage.

Yeah that thread I link discusses the real-world pros and cons of each method based on members that have tried both. Aux seems to be preferred where possible since it gives a bit more control/automation; but even in my own case, if I ever wanted to add a generator I'd have to use Grid input since in my setup, Aux is in-use as an output.

You use the Aux/Gen input "peak shaving" setting to limit power from the generator on the Sunsynk. See if this helps:

I don't think this is exactly possible (stand to be corrected!) but I achieve something similar by setting the 'Power' column value for those evening timeslots equal to my average Essentials Load at night, with a lower-than-100% Batt SOC target. The inverter then limits the load on the battery to that Power value; down to that SOC. (i.e. in my setup, the 'Power' column limits battery drain, but doesn't change charging speeds). I use this to gently step the battery down overnight, powering a load roughly equal to my essentials, whilst leaving some SOC as reserve in the event of a power failure. The closer to morning (and hence sunshine) we get, the lower that timeslot's percentage is.

Note that the 5kW Sunsynk's do still have an internal fan (and it does turn on under high load/PV), but it's much quieter than the externally-vented 8kW fans. (To me, it sounds more like transformer hum than moving/'wooshing' air, pretty quiet.)

Have you checked the LiBMS info screen to verify that power is actually entering/exiting the battery? I ask because the battery bus actually doubles as a PV DC bus for parallel inverters when production is mis-matched, See if this is happening your side:

I did something similar to this. I have both of my own geysers on Aux. (Though their combined rating is still significantly lower than my inverter's: Aux is governed by the same maximum power that limits UPS/Load). My installer did change-over switches to allow us to (manually) swap them over between Aux and Non-Essential. (But in all cases, they're fed by excess PV through zero-export-to-CT). So be safe, by default I just leave the main (most frequently-used) Geyser on Aux in case of a power outage. But if it's sunny and the power is out for an extended period, we leave them both changed-over to Aux because there's no risk of them tripping the inverter if both were to turn on simultaneously. Our 'Aux On When Grid Up' setting is ticked - so Aux stays running regardless of battery SOC when the grid is up, and when the grid goes down, Aux is set to be only on above 90% to protect the SOC in case it's an extended outage. If it's load shedding we might drop this to 50% to allow us to to use the stove (also on Aux). Further to your diagram, we adopted a software approach to do this (using the standard CBI Astute timers that my electrician installed onto the geysers), to achieve round-robin' ing like you're suggesting, where if a geyser is idle (Powered On = Yes and Power Consumption = 0), then we power it off and try the next one. We only do this when the battery is close-to-full (if it's under 80%, we fail over to regular timers). Regarding Aux, think of it as an extension to UPS separated by a relay/switch. So if you want to allow the geysers to turn on only when the battery is above 80% (regardless of Grid), you'd need to set Aux On to 80%; but if you want to be able to fail over to grid, you'd need to combine this with your System Mode Timer to force the battery (from grid) to 80% if PV is insufficient; that way you can still get some geyser heating on cloudy days. So in our case, we just: Have the Aux set to be on whenever grid is up (and on at above 90% SOC when grid is down) Use timers for all our basic heating. We know that our one geyser needs 3 hours to get to full temp and the other needs 2 hours, so they're governed by CBI Astute times to switch them on and off accordingly. To boost their stored-energy capacity, we've cranked the thermostat of the one up to maximum. This means we can heat it beyond our regular requirements (essentially treating it like a battery). Then, in the event that the day is sunny and the battery hits 80%, in between these geyser timeslots, we do additional load-searching ( IF (Powered On = Yes and Power Consumption = 0) THEN Turn-Off-And-Try-Next-Geyser). Because the timers will already give us the hot water we need daily, this load-searching essentially dumps spare PV energy into the geyser which might be useful the next day if it's cloudy; or if hot-water demand is higher than expected that evening. Since we always need hot water (more important than full battery!), we leave Aux on whenever the grid is up, and the battery instead charges from whatever is left over. On a day when we can't heat our water from PV (and need to dip into grid), we usually can't get the batteries charged anyway, which is why (for us at least) waiting for a full battery before heating water didn't make sense. I feel like the most important take-away, in my experience, is that doing a Geyser round-robin only makes sense if you have spare sunshine - so like you suggest (with Aux), Battery SOC % does need to be brought into this equation. If you don't have spare sun, it's more efficient to do the 'minimum' heating your house requires via timers. Or you could perhaps measure kWh consumed by each geyser (against your average daily requirements) and use that as a cut-off when it's not sunny. (If the hardware/wiring route doesn't work out, Home Assistant might be a good software solution for both of these requirements, since it can integrate with both the inverter and your geyser timers.)

My findings were similar to yours, inverter estimate was within about ~5% of the BMS reading, for the few weeks I ran like this.

My understanding is that it uses the Voltage specified in the Battery settings as the 100% point, and then does coulomb counting down from there by measuring amp-hours exiting/entering the battery and deducting that from the "Batt Capacity" specified. I ran in AGM% mode for a few weeks as well (whilst waiting for a battery firmware upgrade) and was pretty impressed with the accuracy, although letting the BMS handle it via LiBMS comms it is still preferable since without it you lose communication when errors occur and other features like dynamic charge/discharge rates that the BMS supplies the inverter. For instance my BMS limits the Max Discharge if one of the batteries in the bank depletes before the other.

Does this imply they'll force all solar users onto Time of Use? Or is there a possibility that post-paid (with it's larger network fee) might be an allowable alternative? I understand the need to have solar users 'pay' for using the grid as a battery, but Time of Use simply isn't going to work for everyone and, as @GreenFields mentioned, might leave those unprepared with sticker-shock when they get their bill if they still have some night-time use. The same might apply for users who don't have the spare battery capacity for this. For my own setup, we'd set a large 'Power' allowance (and a low target SOC %) during those peak times (in the Sunsynk 'System Mode' settings) to permit the battery to drain during those times (and then leave the target percentages, in the timeslots afterwards, high as a reserve for load shedding) - but not all inverters support this level of control. Seems somewhat unfair to owners that didn't see this coming... unless they can perhaps offer a non-TOU alternative that is more in-line with regular post-paid.

The BMS of the batteries can instruct the inverter to force-charge if there's an alternative power supply from which to charge. Not all batteries implement this though. You'll see this indicated on the LiBMS info screen which will include something like "Request Full Charge" when this is occurring. The BMS may be doing this to protect the battery since LFP batteries for example need to hit 100% on a regular basis for cell balancing/SOC measurement purposes (my own AM5's risk losing their warranty this doesn't happen once a week at least). This would also explain why getting to 100% 'fixes' it for you. Here's an example of what it looks like in the LiBMS screen, note the 'Request Force Charge' indicator on the 4th image: https://powerforum.co.za/topic/23770-batteries-wont-go-under-20-soc-sunsynk-12kw-3ph-hubble-am2s/

As Youda suggests, do share your average daily load requirements, since feasibility hinges entirely on consumption. Try provide a busy Winter vs Summer day; and do Weekday vs Weekend. You can probably pull this from the Deye app. My anecdotal experience with the same inverter hardware as you (2 x 5kW) and a similar kWp solar array (20 x 455 = 9.1kWp, vs your 8.7kWp); situated in JHB and assuming sufficient/continuous load throughout daylight hours: Summer peaks at around 60kWh production per day Winter peaks at around 40kWh production per day Summer is far less consistent than winter due to rain (which doesn't happen much in winter); with a rainy spell dropping production by as much as 90% if it's gloomy out. In contrast, moderate clouds (where it's partly cloudy but there's still glare - and no rain on the forecast) only drops production by around 20-30%. The killer is rain clouds. Winter water heating is more power-intensive since the base water temperature is cooler and people tend to use more hot water when it's cold. This seems to be around a 30% increase in our use-case. We achieve at minimum the following targets based on the last year: Sufficient production to run essentials in daytime 99% of days (10kWh per day) Sufficient production to run essentials day and night 95% of days (20kWh per day) Sufficient production to run essentials day and night, and heat our main geyser 80% of days (30kWh per day) Sufficient production to run essentials day and night, and heat both our main and secondary geyser 65% of days (40kWh per day) A few other points related to your post: If you go gas, consider running it in parallel to electric as @zsde suggests so that you can heat your water for free when the PV is good. The last time I did the math, having to heat my water electrically for around one third of the year (like I do now) was dramatically cheaper than using gas the full year. Cooking is the same (since much of our kitchen use is when the sun is out). Also ask yourself if going off-grid electrically is going to make you reliant on the gas grid instead? If so, it might not be worth it (since an electric grid collapse would likely yield a later collapse in gas/fuel as well.) Going off-grid is a somewhat diminishing-returns exercise. At low consumption it's far, far easier, though. Provide consumption figures so we can assist! Prepaid electricity is often the most cost-effective balance between minimizing your system ROI and minimizing your reliance on the grid: we spent a week without power last year in spring and with the exception of everyone sharing the same geyser for a day or two, no-one noticed. If your electric bill is just a few hundred a month, work out how long it'd take for a generator to pay for itself.

This is correct When grid is available, AUX follows the same supply rules as UPS, which (when on-grid), is governed mainly by the table in the System Mode-System1 screen. Think of AUX as just an extension of UPS, separated by a Relay/Switch, which is powered on/off according to the Aux screen settings. If you drop the battery percentages in System Mode-System1 and specify a maximum allowable battery power draw under 'Power' for the appropriate time-slots, the inverter will supply both Load and Aux from PV supplemented by battery, within those limits; and will only hit grid when those limits are reached. You can then use this to cycle the battery down during the day (I go all the way down to ~15%), and then target closer to 100% as sunset approaches.

What app are you using? (The CBI app?) Could it be a bug with the app perhaps? I run our 4 Astute's via the SmartLife app, paired as Wifi breakers (since these are part of the Tuya ecosystem) and the timers work OK. Perhaps try adding them into SmartLife and see if that sorts you out?

Adding a pressure tank wouldn't solve the issue but I'd imagine it would reduce cycling (because the pump wouldn't have to power on as frequently). But yeah, for us, this issue coupled with needing to run off inverters (with limited current/power capacity) for PV has had our household slowly moving everything to soft-start. Our latest air con is an inverter unit: it gradually ramps up power instead of slamming our system every time the compressor powers on and consumes noticeably less overall power to boot. Our non-VSD pool pump is on our inverter's Aux port but because it powers on just once a day, it doesn't matter as much. I've also noticed that some of my LED lighting (especially my smart-bulbs) seem more immune to this issue than others. Sorry I haven't any better solutions for you: hopefully some others can chime in here!

Devices with motors often have large inrush current when they start up which can indeed cause a momentary voltage drop when they start, since such devices can pull 3 or 4 times their rated current when they turn on. I notice the same from my non-inverter air cons (whenever the compressor kicks in) as well as my non-VSD pool pump. Usually its not a safety concern although perhaps it's not great for more sensitive electronics of it happens all the time - but swapping over to a soft-start VSD based pump will resolve this by removing the large current inrush on startup. (My own VSD JoJo pump doesn't cause flickering, unlike my non-VSD pool pump).

I'm running a pair of single-phase 5kw's in parallel, I've had solid service from [email protected] - drop them an email and provide the serial numbers for your unit and they should be able to assist and remotely update your firmware.

Yeah the CBI turns it off on a timer. We could actually make it smarter (eg turn off when there's no Solar due to rain) with SmartLife automations, though it's not really energy-intensive enough to make it worth doing... (I do this with the other CBI on the swimming pool to save grid consumption). Supply to the house is fed from both tank and municipal simultaneously (via what looks like a plumbing t-junction!) where the installers balanced the two, with the pump kicking in at a certain demand-pressure: the installers set it such that if we turn on the tap a little, it stays off; but a tap all-the-way-on triggers it. This means that there's sufficient pressure from municipal supply to run at night by just turning the pump off, whilst it gets mixed into the supply during the day (to cycle the water in the tank). Agreed: we've set out tank-fill tap/lever to pretty low to cut down on the pressure consumed by filling, but this is definitely still a concern. I see it as a stepping-stone to going independent with a borehole that fills the tank during the day using a large borehole pump, with the smaller JoJo pump running all the time from the tank. But that'll happen once the PV has finished paying for itself!