SellusWallace

Is this remedied by simply connecting the supplied cable from the inverter COM port to the battery COM port (which was not done by the installer) or is there more to it? Thanks @Coulomb, how were you able to distinguish this? Also, what would this mean if we were to eventually add panels later? Thanks for this, I set the bulk charging voltage back down to the 56.4V it was before the installer recommended I bump it. Would you advise I lower this to 56V? This is super interesting. Looking at the inverter display, the utility voltage varied between 226V - 228V on the occasions I checked. Am I correct in understanding that this is not a solvable issue as this is due to the design of the relays & that it can be influenced by many factors? Thanks again for the wonderful feedback everyone, you all are awesome! 😁

Thanks for this insight @Kalahari Meerkat, this is super useful. Might the < 100% SOC be caused by the current constant load shedding that the battery simply does not get enough time to fully balance out the cells? Thanks @Bobster., that is useful information. I don't believe high load would be the reason for my issue as these interruptions occur when total household load is well under 1000W according to the inverter display. I've had two load shedding slots today where there were no interruptions & the load was approximately 400W - 500W at both times. So while the battery capacity definitely isn't up to par for a 10 kW system, I haven't yet exceeded 5 kW yet at any point to my knowledge. When mentioning the occasional interruption issue to the installer over the phone this morning, his response was that that is expected behaviour because "this inverter is not a UPS, it's line-interactive, the inverter is not always running, so therefore there will always be an interruption when the power goes out before it switches to battery". I mentioned that if that were the case, the interruption would happen every single time the power goes out, not only occasionally to which he responded that he will need to come check it out. Still waiting on that visit though. 🙂

This is indicated on the battery LCD itself as per below image (coincidentally it was at 91% at that point) but I'll try & find the appropriate software to try & get more detail out of it. Going to raise this with the property developer as it is their extras list which advertised this as a 10 kW system. Am I correct in calculating that your battery has 16 cells? How does one determine how many cells are in a particular LiFePO4 battery? Sorry for the noob questions, still very new to all of this. 😅

Thanks so much @Kalahari Meerkat & @Sc00bs for the input, you raise some interesting points. I hadn't thought of doing the calculation of battery discharge current x voltage & looking at the math, it makes sense that this is not a true 10 kW system. Indeed, the wording does say 10 kW, so it's supposed to be a 10 kW system. But if the supplier can't calculate the appropriate battery size for the inverters they install & they can't be bothered to space the two inverters appropriately for ventilation, this casts some doubt on whether they really know what they're doing. I highly doubt presenting them with this information will result in an "oh shucks, you're right, we'll come & install another battery for you" but it's worth a shot. @Sc00bs, good shout on the efficiency aspect, though I would happily deal with the slight drop in efficiency rather than risking some machines which run 24/7 with unsafe shutdowns. Regarding the 92% max SOC, I had a call with the installer this morning who suggested I bump the charge current from 40A to 50A & the bulk charging voltage from 56.4V to 57.4V but that didn't seem to address the issue, so he needs to come by later today to have a look.

Hello lovely people! I recently joined this forum looking to get some insights around a new backup power installation & thought it was finally time to ask for some advice as the frustration is getting palpable. I also apologise in advance for the lengthy post. First some backstory: We recently purchased a house at a new development & we were delighted to see that one of the optional extras we could pick was a backup power installation to alleviate the load shedding woes. So naturally, we picked that option as the price was incredibly good & I felt really chuffed about getting a good deal. But as they say, you get what you pay for... The spec sheet for the setup on the extras list was not particularly detailed - all we knew was that it was a 10 KW setup, inverter + battery only, no panels. Looking at what colleagues were paying for solar setups vs the price we paid, I started to think that they were going to wire a few USB power banks together & call it a day. We moved into the house about three weeks ago & the installers came to install the inverter & battery shortly after & to my surprise, they installed two 5 KW inverters in parallel with an actual lithium battery. I was gobsmacked that we got one of the fancy batteries everyone was recommending & proceeded to do a little happy dance when the installer was looking the other way. Fast forward a couple days & I was feeling proper chuffed. Coming from an inverter trolley setup at the old place which could only power the router & TV, this new setup was running THE WHOLE HOUSE. I didn't even notice when load shedding kicked in as the lights didn't even dim & I could continue sucking at Modern Warfare for at least a couple of matches. All was good. Until it wasn't. I started to feel like I was missing something. You see, all the cool kids had these fancy apps & monitoring dashboards to see how much power they were using, what the battery levels were & all that neat stuff. I felt like a caveman needing to walk to the garage & look at the inverter to see if the power was on or not. Something needed to change. I perused the manual which came with my inverter to see if there was some kind of companion app I could download. No dice. There was only a QR code which directed to an obscure spreadsheet which I quickly dismissed as confusing. Then I remember seeing some software called Solar Assistant & proceeded to check if my inverter was supported. Initially I was thrilled - looking at the pictures provided, it seemed my inverter was a Voltronic inverter. It looked like a Voltronic, sounded like a Voltronic, smelled like a Voltronic. The manual even resembled the sample one provided in the Solar Assistant docs. Oh, happy days. I followed the instructions to install WatchPower & SolarPower, spent a couple of hours hunting down a USB printer cable & was off to the races. I booted up WatchPower, plugged the USB into the port on the inverter and... nothing. Okay, I thought, seeing as my inverter had "hybrid" in its name, I shall try SolarPower instead, and... nothing. Balls. This is the part where I stumbled across this forum & learned about these things called clones. Reading up a bit on the matter, my understanding is that for this particular class of inverter, there are the original manufacturers, Voltronic/Axpert, and roughly 5 thousand distinct clones which rebrand these models & put their own spin on them. My particular model is a SAPPHIRE HYBRID 5048 PV18-5048 VPK. Googling this takes me to this spec sheet, which says it's a MUST inverter, which I understand is a clone of an Axpert. So I have a cover version of a cover version of the original. I have a LimeWire edit of a Bump remix of the original song. This did not inspire confidence. After some more investigation, I learned that the MUST inverters' RS485 & USB ports operate over a binary protocol instead of an ASCII protocol (Solar Power Monitor 2.2.81 alternative - Design Software - Power Forum - Renewable Energy Discussion), hence the incompatibility with WatchPower & SolarPower. These MUST models only work with another piece of software called SolarPowerMonitor. I didn't explore that yet because another issue crept up which felt more pressing than monitoring. One afternoon I came back from work & spotted something that filled me with dread: the clock on the microwave was reset. This could only mean one thing - the power went off. To confirm, I also checked my router uptime & saw that the power was interrupted right around the time a load shedding slot started. I immediately initialised the only monitoring solution I had and walked over to the inverter screen to see what was up. Both inverters were up & running with no faults & I checked the battery display & the battery was fully charged. The only thing that was different was that the master/slave configuration seemed to have switched around. The inverter that was master was now the slave, and the other was now the master. A case of role reversal. I was curious as to why that would have occurred, but my initial presumption was that when the grid went down, the inverters switched roles & because they did, the transfer from grid to battery was just not quick enough and this caused the power to drop for a split second, resulting in the microwave clock reset. This was a complete guess because I am still a complete noob when it comes to how these things actually work. Nevertheless, this was concerning as there was now this looming risk that sometimes - not every time - there will be a brief power drop when the grid goes out. This is bad for sensitive electronics & meant that I couldn't reliably keep working on my PC when the power is due to go off because there's a likelihood that it will briefly cut out. Plus, I would always need to re-adjust the microwave clock & that is just not on. After this happened a couple more times over the next few days (the increased stages of load shedding did not help in this regard) I delved into the manual again. I spotted a setting for 02 - AC input voltage range which affects the transfer time. The default APL (appliances) mode indicates a transfer time of 20ms (for home appliances) whereas the UPS setting indicates a transfer time of 10ms (for personal computers). Hell yeah, I thought to myself. More faster = more better right? Perhaps the default mode did not switch over fast enough & that was causing the brief interruption. I wrestled my way through the settings & managed to change the mode from the default APL to UPS. Job done, time for a drink. The next few days it didn't skip a beat through all the load shedding slots. I felt like a genius for figuring this out. That was until this past weekend when I went to reheat some food & I spotted the microwave clock. It read: 0:00. 😐 These last two days it happened twice again. Once during a 6:00 slot & another during a 22:00 slot. I witnessed the 6:00 occurrence where it seemed like a 2-3 second interruption at least. It is worrisome & I'm not sure as to what the cause might be. There is also another worrisome thing I noticed whilst constantly checking the battery level during this last week's hectic load shedding: the maximum SOC as reported by the battery is 92%. I contacted the installer about this & he is yet to come around this week to investigate as he mentioned that the voltages might need some tweaking. It's worth mentioning that 14 - battery type in the inverter settings is set to USE (User Defined) with custom voltages & the inverter isn't connected to the battery via the CON port, so I'm uncertain of whether the BMS is being leveraged or not. This battery is an Esener 51.2v 5.12Kwh 100Ah. Anyway, apologies for the long story, I just felt that some context would be helpful. My questions to this wonderful community at this point are: What could be causing the occasional interruption during switch-over from grid to battery? Is the interruption a common occurrence with parallel connected inverters? Could the lowered battery SOC indeed be voltage-related, or could it be a sign of a bad battery or early degradation? Any insight will be greatly appreciated. I've attached some images of the inverter/model detail if it would be helpful. Have a fantastic day!