wolfandy

My initial reaction would be that it sounds too much - but I guess it depends on what distance you need to cover Can you please provide us with a bit more details on your current Wifi setup as well as distance and environment (e.g. line of sight or number of walls in the way) that need to be bridged? And what Unify equipment did they quote you on? And other than your Pi, do you plan to use anything else on that section of the Wifi (meaning do you require additional bandwidth)?

Yup. Installed a Victron 250/100 MPPT with 12x 380W panels and a VE.Direct cable to my ICC Raspberry Pi. Everything works like a charm and I am very happy with my setup 🙂

Absolutely overpriced. I use a Samson equipment rack at a fraction of the cost of those cabinets. As the Pylons are standard rack-mount size, no need to buy special cabinets Definitely the best choice Just one word of warning: Once you start down this path, you will eventually end up spending more money. You will get by with a single Pylon, but then it would be really nice to have a 2nd one to run a couple of extra things during loadshedding. And then, since you already have the inverter and Pylons, you might as well add a few PV panels to start banking savings from the inverter/Pylon investment that you have already made 😝

This would mean an average draw 1.56kW - which is close to what a single Pylon can provide for longer periods of time (37A x 50V = 1.85kW) And if you did draw that amount for the full 2.5h than obviously a single Pylon would not suffice Yes, at the beginning I only had my light loads on the inverter, which kept my load constantly under 700W for the duration of the loadshedding Just keep in mind that you obviously have efficiency losses in the DC-AC conversion, which means that 100W of AC load do not equal 100W of DC load on your Pylon. So you want to make sure that you leave a bit buffer in your calcs Pylons do not like more than 37A either in either direction for an extended period of time. In theory that means, that you can recharge the Pylon in approx. 1.5h if you can provide it with exactly that charge (not sure how finely you can program the AC charger on the Kodak but on my Axpert I can only select in 10A increments, which means that I would only charge it with 30A and hence it would take a bit longer)

Have you measured the wattage that your essential loads will draw? And what time do you want to power them? If you are talking about roughly 400-500W (which would be my guess based on your description) for the typical loadshedding duration (2.5h), then a single 3.5kWh Pylon will be enough for you (500W x 2.5h = 1.25kWh vs the Pylon able to provide 2.8kWh @80% DOD) I used to have a bank of lead acids when I initially installed my backup system in 2015. The batteries went through less than 50 cycles and by 2019 were basically dead (end of lifetime). Lithium batteries do not have the same problem of dying even without usage. I do not know what current lead acid prices are, but I would guess that a set of lead acids that at 50% DOD provide you with similar capacity as the Pylon @80% DOD will cost you more than half of the Pylon - which means that if you plan on keeping your system for more than the lead acids' expected lifetime, the Pylon will actually work out cheaper in the long run. Plus having the ability to (a) have something that is suitable for expanding your system with PV and (b) add more batteries as you grow your system That's also what I did: Replaced my lead acids when they were dead with a 1st Pylon, then added PV, and eventually added Pylons #2 and #3 As long as the 2.8kWh usable capacity is sufficient and you can ensure that you do not draw more than 37A (approx 1800W) from your Pylon, I would strongly recommend that path

To my understanding this is nothing to worry about - it is just the new battery getting settled I also recently added another Pylon to my system and am seeing exactly the same as you. On some days the new battery is closer to the older ones, one other days the difference is a bit higher. I believe over time they will all converge (as my other 2 also did) Same thing also here. Again, as far as I understand nothing to worry about

Ok - thanks I am running a similar system to yours (also 12x 380W panels and 2x 5kVA Axpert) but with lithium batteries. I have everything except for heat pump / geyser, washing machine, and tumble dryer running off the system. And as you can see, it is having a significant impact on my Eskom usage (Total Load vs Grid Used): Obviously if I put very high loads on the system (e.g. run the oven @3kW for 1h like yesterday), then I also pretty quickly get to the limits of my system (even with 3kW of PV on a winter day like yesterday it means that during that time I was drawing on batteries as total load incl. rest of house was 4kW). Hence my Eskom usage yesterday was significantly higher than usual

One other basic question: What is your setting #01? SBU, SUB, or UTIL? And your paralleling setup is correct? All comms and current sharing cables connected correctly? And setting #28 on both to PAL?

Thanks Piet Your Back to Grid setting (#12) is too low at 46V. Thereabouts is where the Pylon BMS shuts down to protect itself - which is why your system then completely shut down. As per @Coulomb recommendation above, you should set this to 48V. But instead of having to do this on the Axpert itself, you can more conveniently do it through ICC. Here are my ICC settings: As you have 4x Pylons, you can set both Max PV and AC Charging Current to whatever the highest value that it will allow (as long as less than 140A) You can also increase the Bulk Voltage to 52.5V instead of my 52.5V (I have also done that since this screenshot was taken) My Back to Discharge value is significantly higher than Coulomb's value as I want ICC to control the switching between battery and utility instead of the Axpert itself I've found that my SOC-based switching back to utility (see below) typically happens at voltages above 48V, so I leave the Back to Grid Voltage setting at 48V as a safety net The other very important setting is under the Battery tab: Here you define at which SOC (from Pylon BMS) you want ICC to switch the Axpert. Here you need to experiment a bit. For the To Grid value you need to keep in mind that the Axpert will still draw its self-consumption from the battery even when running on utility. So you need to keep a few % as reserves to make sure that the Axpert's self-consumption does not bring you to below 20% SOC until there sufficient PV to balance the self-consumption. For the To Solar SBU value you need to see at about what time you PV production exceeds your load and what the SOC is at that point (to avoid multiple switching back and forth in the morning) The other setting that I noticed is #28. If I am not mistaken, you inverter is set to parallel mode. If you are only running a single inverter, I believe you should rather that set to single. If I am not mistaken, you can only change that setting when AC, PV, and loads are disconnected and the inverter is switched off (but batteries still connected). At least that is how it works on my old Axperts For the rest of the settings I will leave it to our experts ( @Coulomb) to comment if anything else should be changed

Hi Piet it sounds like your Pylons are getting drained to the point where they shut down - which means that the setpoint for the Axpert to switch back to Utility is set too low. When you say that you have a Pi, does that also mean that you are running ICC? And do you also have the cable to connect the Pylons to the Pi? If you are running ICC, then we can set everything through there. If not, we will need to go through the individual settings on your Axpert. Please post answers to my questions above - and then we will take it from there

Ok. Then it seems that it is not a Pi problem (power supply / SD card) but rather an ICC stability problem I've also had stability problems with ICC every now and then, but mine are occurring when I am making changes to settings (and then ICC suddenly dying on me). I have not experienced ICC dying while simply running and not being touched If the support is talking about a hardware communication loss, what solution are they proposing?

Is the Pi rebooting or just ICC restarting? I've sometimes had ICC die on me but the Pi was still running fine If the Pi is rebooting, have you tried running the Pi without ICC for 24h to see if it still does a reboot?

Thanks. My (old) Mecer is rated for only 3kW PV. So just wanted to check that the PV array is not oversized...

Ok - I thought the drop to 0 would just be for a sec or so... What PV capacity is your Mecer rated for?

There is no downside to doing so. But you will not be able to have the Mecer/Axpert directly communicate with the BMS. The upside that you do get from the BMS is the additional protection of the BMS against abuse of the battery (e.g. overcharging or depleting below safety limit). I am running Pylontech batteries with built-in BMS (to my understanding similar to your Dyness) with my Mecer/Axperts and the system runs great (but with ICC controlling the system) As @plonkster has explained to me in this thread, "it is the MPPT doing a rescan to see if it can find a better power peak". His explanation is on a Victron MPPT, but the same holds true for the Mecer/Axpert MPPT. When I had my PV directly connected to the Mecer/Axperts, I would have the same phenomenon - just less frequent than on the Victron MPPT

I do not know the Dyness at all, but this sounds a bit low. I would assume 80% DOD, which would mean 2.56kWh available for use Correct. The MPPT will throttle back to whatever power is required by the loads It works ;-) The biggest problem of the Mecer (or Axpert) in this regard is that it cannot communicate with an external BMS and works on it's own voltage measurement of the battery to determine when to switch, which might in reality be significantly different to the actual SOC of the battery. The software ICC offers a work-around for that as it is able to communicate with some BMS's (not sure if Dyness is among them) as well as a Victron BMV, which can otherwise be used to determine the SOC of a battery. ICC then switches the Mecer/Axpert between Utility and SBU based on that SOC data, which is much more accurate. That is what I am using in my own system and am very happy with

Cool - happy to hear that it's working 🙂 I have my system running in SBU (Solar - Battery - Utility). As there is no PV available for the Axpert, it will use batteries - which is where your Victron MPPT is also connected to. Once your MPPT production drops below your load, the batteries will automatically provide the difference. If you do not have sufficient battery capacity to get you through the night, Axpert will change over to Utility based on your "Back to Grid" setting One question about this: I do not think that VenusOS will give you any benefits at this point as it cannot control the Axpert. I am running ICC on my Pi, which by now is also able to communicate also with a Victron BMV and MPPT. ICC can then switch your Axpert between SBU and Utility based on the SOC calculated by your BMV rather than the Axpert's guesstimate. If you already have a Pi, then the cost of the software is relatively low. It works great for me

I have learned that as a general rule of thumb you can expect 5x your installed PV capacity as total output on normal (non-cloudy) days. So in your case that would be 5*12*335 = 20kWh. This of course is based on the assumption that you have sufficient loads to consume the production and that your MPPT does not throttle due to insufficient loads. As an example, my system has too much PV at the moment and around 13h30 my batteries are already fully charged, after which the MPPT throttles back. So even though I should expect around 23kWh from my system, I am only getting around 18kWh. Once my extra Pylon battery finally arrives, my system should be better balanced and I should be getting closer to maximizing my PV potential every day. 80% as general rule for max average output is correct. You will have hotter days on which you will not achieve that and you will have colder days on you will get higher output. You will also get short peaks where your production might be above your installed capacity Some questions/remarks in return: The Dyness is a 3.5kWh module, correct? If yes, then this would be very light compared to your installed PV capacity and you would most likely have the same scenario I described above Depending on the specs of your panels and the MPPT in the Mecer, you might be getting very close to (or even beyond) the point where the Mecer starts derating the PV input

Am using 52.2V and 51.8V - and my system is running without any problems. But I am also cycling my Pylons every night Only slight oddity that I see every now and then is that the Pylon BMS reports 101% SOC

🙂 Mine is actually installed in the DB board. I originally had the pool pump still running straight off Eskom (when my system was only UPS) and only moved it across to my inverter DB board after I added PV. My installer managed to find space on the side of the DB board and squeezed the Sonoff in there

I will let our resident experts confirm, but based on the info from this post your sticker would point towards a clone

Am not sure I understand your question Am using a 10A Sonoff for the pump. Has been running for 6 months now without a single problem

Ok - I am not an expert on this, so I am hoping some more senior forum members will correct me if I am wrong Your panels are 72 cells and 44.8V VOC. If they are connected 3S, then my guess would be that you are getting too close to your max operating voltage of 115VDC and your Axpert starts to derate But somehow I do not think that this by itself will explain that you get so little out of your panels Do you get shading from anywhere on your panels during any part of the day? +1. But do you think the angle will cause him only getting 600W out of his 1800W of panels? I simply do not have enough experience to be able to answer that...

He states that he has 6x 330W panels installed - yet he barely gets more than 600W out of them (and hence the low W into the batteries). Does that not sound strange to you?

Don't you have a changeover switch installed that you can simply bypass the inverters for a while and run off utility in the meantime? + 1