GreenFields

Layman's 2c. Pure speculation. Making some assumptions, might be wrong, might mean nothing, to be checked with the manufacturer(s). I would put a greater gap between the Over Discharge SOC (currently 5%) and the Force Charge SOC (currently 4%). How I'm understanding it is that you are allowing a deep discharge of the battery down to 5% capacity, say for cloudy weather. And when the battery goes any lower, ie. at 4%, the system will kick in to force-charge the batteries and protect against a discharge so deep that it causes permanent damage. I see you're limiting the charge rate to 200A under normal circumstances, but the question is whether this "rescue" charge is overriding all other settings and prioritising the battery. In that case, with 6x Hubble AM2's connected to 2x Solis 6kW inverters, you'd be topping out at 2x135A battery charge current. 270A at 53V charge Voltage, would give you 14.3kW power demand, and that could trip a 60A circuit breaker at 230V (around 13.8kW). I know you say you've got enough PV for your loads, around 7.5kW off the panels, but you could easily have a start-up surge load exceeding that when your "low" load kicks in, and in that case it's possible that the battery Voltage sags down momentarily to indicate 4% SOC. And off we go. Or I'm talking utter rubbish that I know nothing of, but at least it sounded plausible in my head.

There are some earlier threads on this topic. Sunsynk likely won't have this function in their firmware, because the original equipment manufacturer, Deye, also does not support it in the firmware. I have previously enquired with Deye if they could do it, but the answer was negative, apparently they would have to change their inverter too fundamentally to support it. Or so the story went at least, but also, that's now some time ago. Maybe we're lucky and the story at Deye changes if one of their major re-brand business customers (Sunsynk) asks the question. The function on the Deye-brand inverter is called: Zero Export to CT. Not always certain what the naming is in the Sunsynk firmware, but it's the work mode setup where you send power from the solar and battery to power your whole house, not just the essential loads, but also the non-essential. Where it says "Limit to Load" you make sure the box remains un-ticked. I understand that you want to be able to top up from grid without draining the battery, and in that case the workaround might not be a great solution for you. What I tend to do is to heat up my geyser from grid just before sunrise and I do a topup shortly before sunset, and that meets my needs automatically. In each of those slots whenever I heat the geyser I limit the battery power output setting via time-of-use. The crux is, you want to be able to change your work mode depending to load-only whenever you want your geyser to run, and that is not possible in the firmware, you'd have to get some external assistant to set up such a type of automation.

Use Zero Export mode, and do not limit to load. Set up the Sunsynk's Time-of-Use function, and align one of the time slots with when you want to run the geyser. Whenever the geyser is running, set the "Power" value for that Time-of-Use time slot to zero [ 0 ]. Or otherwise set the power value to around 500W or whatever your baseload is, and that is all you will be drawing from the battery. Put the geyser on a timer to automate the heating time in alignment with your TOU slots. Works okay, but might not be a perfect solution for everyone.

I'm not sure if you're seeing the function correctly. The Smart Load/Aux port is not dependent on how big your load is. It turns on depending on how much solar power you have available. So if you set it like this and your panels can generate above 0.5kW, then the geyser should come on drawing the full 2kW of power, but it might not all come from the solar, it might also come from battery and/or grid. Personally I'd set it to a value where the panels can carry the majority of the load, and try to spare the batteries from powering the geyser.

How much of this gas energy consumption can you sensibly transfer to electrical consumption? I'm not talking about upending and getting a new hob, rather if there's a grill microwave, airfryer or other small electrical device already there, that could be used more frequently, that could reduce gas expenses. But that is only a small chunk of the 10kWh you are giving away daily. Maybe your next car could be hybrid or electric, because you could do maybe 60km per day for free on your surplus power.

A number of folks are adamant in this thread about NOT registering with Eskom, but that somewhat defeats the purpose of understanding the experiences of people who actually DO have SSEG connected. This setup is highly skewed towards benefitting Eskom, ie. you've exported 3MWh, or around R10,000 of electricity at retail pricing, but you've received just R350 of value in return. Leaving aside the fixed charges because on some level it's always fair to pay infrastructure availability charges, but this is a raw deal. I mean, thank you for helping Eskom avoid loadshedding and doubling their profits, but I just wonder whether you can't use the electricity you're generating more effectively for yourself to improve the return to you on your investment.

This type of variation can be completely normal if there is a hazy sky. If you live along a dusty road, maybe check if the panels aren't getting a layer of dust settling on them. It could also depend on your loads, for example if the battery is getting nearly full, it might start drawing lower power from the panels.

Personal 2c only as a customer perspective. I don't know LBSA's products directly, but I'd say that being on the inverter manufacturer's compatibility list would be an important factor in my decision. Beyond that, on the question of whether a 16kWh battery is something worth considering... Look, I like the fact that these batteries now come with a lower cost per kWh than ever before. It's still a bit much for someone who is just in the market for a small 5kWh backup, but the price is definitely becoming an alternative for someone who was just going to install two 10kWh batteries. Only thing then, you've got to have a real capability to deliver 8kW or 10kW of power as 2x 1C batteries would have given you for it to be a real alternative, like a 200A discharge to be full usable with an 8kW or 10kW inverter, not just 0.5C or 150A output or thereabouts. That's not enough. And going much higher than 10-15kWh in any case doesn't make sense for me for the most households or the average household, not talk about rich people here. We're not ready yet for selling back to grid, but if TOU export rebates become more user-friendly, that's an avenue worth exploring for the future. Where I see real growing potential for a 16kWh battery or two (or 3?) is for daytime power storage for nighttime charging of electric vehicles and hybrids, that come with maybe a 30-40kWh total capacity or more. Of course you could charge overnight from the grid or a public high-voltage DC charging station, but if you prefer environmentally friendly power, or want reliable mobility free from loadshedding fears, then having your own cheap big batteries and maybe a cheap dedicated 6-8kW off-grid inverter for this function could make sense.

It's difficult to comment without knowing how much battery storage you've got, and how much you use throughout the night. But it makes perfect sense to limit the drawdown during the evening, so that you have enough in reserve in case you need it for loadshedding or just to last through the night. If you're like most folks that use lots of power early evening for cooking, etc., I'd consider allowing the power to drop down to maybe 50% betwee 5pm and 9pm, but then keep that 50% in reserve until sometime early in the morning. That is, you can do two or three steps or SOC levels during the night.

It's a known issue. The thing that you want to do is not directly possible within the firmware on the Deye. You need to a third-party automation assistant that can change the work mode depending on the time of day. Don't know which one though. Alternatively, a workaround stick to the daytime mode (un-tick Limit-to-Load), and on the Time-of-use screen, you can set Power limit value to something low like 300-350W. Any demand in excess of that value will come from the grid. But you ideally should get at least one more battery to help make better use of the generation potential of your panels.

If the panel Voltage is a factor, if you want a greater margin of safety, you could consider the Solis 8kW Pro-model: S6-EH1P8K-L-PRO, which is rated to take 600V. Still to be cross-checked for any other requirements, I'm just putting it out there as a possible solution to one issue.

Laymans' 2c. To be checked by installer, considered at own risk. Did you try looking for this Trina Solar panel from Voltex? Trina Solar Panel 415W TSM-415DE09R.08. https://www.voltex.co.za/product/trina-solar-panel-415w-tsm-415de09r.08 According to the spec sheet it's got Isc=10.64A, and Imp of 10.11A. https://static.trinasolar.com/sites/default/files/Datasheet_Vertex_S_DE09R.08_EN_2022_PA1.pdf If you can get this new with warranty/support from a nationwide retailer, I think that would be first prize.

@DylanP As above, no need for grid-tied hybrid inverters if staying off-grid, maybe two 6kW Deye off-grid inverters, and put the savings towards batteries.

The question of whether to go with AC-Coupling or DC-Coupling should also consider when you will be needing the power. If you're using the power mostly by day, maybe exporting it, or consuming it instantly as it is generated, then it's probably better to go with a grid-tie inverter on the AC (load) side. If you're going to be storing power in the batteries to use later, then it's probably better to go with an MPPT on the DC (battery) side. The difference is in how many DC-AC and AC-DC conversions you will be doing, ie. efficiency plays a role. But it's also taking into account that the inverter's rated capacity is likely to be the bottleneck in your system.

Two main concerns. First is is to understand the total energy requirements better regarding generation and storage ie. when does the Kilawatt show your current heating of 11kWh is taking place, day and/or night, and will the system be able to generate and store enough total energy you need, in whatever size geyser size you have on hand, to cover evening and morning hot water needs. Worst case if you've got say a 150l geyser and it gets heated up effectively for 1.5-2 hrs during the day, then emptied in the evening, and re-filled cold, and heated for another 1.5-2 hrs during the evening, you should check whether daytime-only heating is going to produce the real-world savings you're looking for. Second concern, is why you are looking to use an unapproved panel configuration. Just reading through the Elon manual, it's quite extensive in its listing of recommended/prohibited/sub-optimal panel arrangements, and says that any alternative setups should be checked with them. My concern is, even if it works technically, that they may not support warranty claims on panels that they didn't agree to. Also, just looking through the manual regarding energy requirements for various cities, it seems you'd be better off in Durban to go with around 3kW of panels, probably in a parallel configuration as per the manual. Side-comment: Having 3kW of the same panels once-off is also "safer" to upgrade with, ie. to transfer to one MPPT of a 5-6kW inverter later, without having to mix and match panels. I understand that financing is a constraint, and I love the idea of not paying a premium, but I also hate waste and risk.

I saw that comment, which is fair enough of what's been happening locally in the past. But I'd guess that the new local rep of a battery manufacturer could have access to international recycling facilities, if they can gather up enough of the local stock through a buyback programme to make exporting it worthwhile. Not saying this is what they are doing, but I think the business model could be workable, considering that they are also selling new product in its place.

Okay, so then the R2K on offer (approx $120 USD) is about middle of the road or average for the reported international scrap value of the battery. Just stating the obvious. I'm sure the newer batteries are better and more desirable, but each one must maar decide for himself how much his old generation battery is still worth to him.

Out of interest I just did a Google search using the words: "48v 75ah lithium battery raw material value in us$" and got the AI answer: "The raw material value for a 48V 75Ah (approx. 3.6 kWh) lithium iron phosphate (LFP) battery is roughly $220 to $300 USD, based on average cell-level LFP raw material and commodity benchmarks" I make allowance that this may be inaccurate, but for sure I'd want to dig deeper before thinking even for a second of selling some fully functional built up batteries for possibly half the cost of the materials used to make it. Don't care, not leaping before looking.

Some other stats worth noting. Maximum Open Circuit Voltage is 500V - never exceed this value. Other thing is that the battery charge spec is a maximum continuous charge of 100A, but a recommended charge of 40A (0.2C), while the solar charger can handle 200A. The BMS seems to allow 200A surge discharge for 16 seconds if I'm reading right (subject to correction). I suppose it is what it is and it does what it says on the box, but I'd have liked a higher continuous battery charge/discharge rate to support the rated 10kW for longer in the absence of the sun, if this is being sold as an all-in-one 10kW solution. In any case, I think you could re-evaluate if you need the full 10kW of panels with 200A charge capability, if the battery can't handle it. Personally I'd install just 5.5kW at first, say 2.75kW per PV input, or say 5x550W panels per PV input, and then later evaluate if you want more. Depends on the rest of your daytime loads.

For surviving on minimal power, a 400W wall panel heater per room, then close interleading doors and only heat the rooms you need. Or electric blankets.

The Smart load uses a separate port. Please confirm, or check whether the geyser is connected to the "GEN" port on the underside of the inverter. It might be that it's just connected as a non-essential load, ie. on the Main switch as a household load, but excluded from the backed up home circuits on the LOAD port.

Please confirm your inverter model, and the type of grid supply or wiring layout. I can't find any info on an 8kW 3-phase Sunsynk inverter (assuming you meant kW not kWh). Or are you saying that you have 2x single-phase inverters, each connected on one phase within a 3-phase power network? What phase(s) are your loads on, and which are the inverters on?

This issue cannot be resolved with a connection or a setting. It is a characteristic of the panel that is not optimal for the inverter's charger type. Also, considering that the house is already facing around 20 degrees East, those panels are actually facing a bit towards South-East, further reducing the generation capacity. Would there be too many shadows if you fit them to the main roof facing North-East? Unfortunately you've got a complex situation with possibly no easy solutions.

Layman's 2c, use at own risk, or get advice. Some points to consider all the same. You've got an inverter with a 1200W PWM charge controller. In Winter that's just not quite enough to keep the battery charged. On average, touch and go, under the best of conditions in Winter, it's just-just sort of okay, but most of the time not, and if you're intending to run daytime loads from it as well, then you just don't have enough power generation capability. On top of that your setup is likely not optimal to begin with. I'm assuming that your 2 x panels are connected in parallel, or it would have exceeded the inverter's max VOC and caused a failure. If this is not already in parallel, you really should change it over to parallel. But your panel's Vmp isn't ideally matched to the inverter. Better would have been to use a panel like the Canadian Solar HiKU6 CS6W405MS panel (x3), because the Vmp spec is better aligned with the battery charging Voltage. Unfortunately you've got a 25% loss of efficiency with the current panel right out the gate. You could lower the discharge cut-off Voltage to 20V (spec as per the battery), ie. discharge it deeper than the inverter is doing now. And then I think you should change from SBU mode to utility mode, ie. just keep the battery and panels on-hand as a loadshedding solution, without trying to power the whole house from it permanently. You'd have to do a more drastic upgrade, like changing to a 24V MPPT-controlled inverter, and adding maybe another two panels, before you can start thinking of running daytime base load and then still charging the battery by day for draining at night.

Given the East/West split, you won't see the full 7.7kWp anyway, the peak should be lowered to around 7kW at mid-day in high summer (you can check it on an online solar calculator). Maybe calculate by another route and compare it to your current mid-day peak in summer, then add another 17% on-top of that. I'm not in a position to give a comment on the safety.