Toxxyc

Yeah overall it doesn't really change anything, except now it feels to me like something is wrong in the system. I have this constant worry that something is amiss, even when everything now works perfectly fine. Voltage mode works. System was optimised as bit more as well, and now the batteries also charge a lot faster. Dunno why, but they set the batteries to only charge at something like 680W max per battery, so it took the whole day to charge. Turns out they can charge a lot faster than that, and can now go from almost dead to full in like 4 hours, which is epic and opens up my mornings a lot more.

So after a lot of tweaking and testing, the problem can't be identified. The installer was here, they tested all the batteries, removing them one by one from the system, and the problem remains. As a solution, the system was set to lead acid on the batteries, the parameters set properly, and now the problem seems to be gone. It's REALLY weird.

I've spoken to the installer, and his managing guy says there might be a faulty BMS. It's very weird. For example, yesterday during the day, when batteries are charging, two will flash 60% to 80% SOC (the 4th LED flashing green), while the other two will flash 40% to 60% SOC (the 3rd LED flashing green), with the inverter reporting 71% SOC. So I prioritized battery SOC yesterday (usually balance it with running devices in the house like geyser and ACs and dishwasher and so on), so that I could get maximum charge earliest in the day. Around 14:30 I hit 100% SOC as reported on the inverter (while using power for the other stuff as needed), so I started switching off batteries in the line. However, they all reported 99%~100% SOC. So I figured "finally they're all full together" and continued as normal. During the night we ran the AC in the bedroom for 30 minutes at a time just to raise the room temp a bit, as we usually do, and we woke up to again 54% SOC on the batteries (as reported on inverter). So at 06:00 I switched on the AC again. I ran the AC until just before 07:00, when I switched it off. At that time, the battery SOC was reported at 42%. The second I switched the AC off, the SOC tanked to 20%. It wasn't gradual, it was instant, as can be seen on the graph as well (graph's time is an hour early, ignore that): So it looks like at least one of the batteries have got a faulty BMS. The problem is getting worse, so it also makes sense. It could be that at 42%, two of the batteries switched off, resulting in the remaining SOC halving to 20%. That's my best guess at this stage. I'm in talks with my installer to see how we can get this sorted. I have a genny, but can't run it 24/7, so this needs to be sorted ASAP.

Yeah I'm easily generating 40kWh+ per day in the bushveld. It's just getting everything else in the house running with the batteries charging to full that's also a challenge, but I think today I should manage. I'll get them all charged until the system reads 100%, and then start switching off and letting the lower batteries charge to full as well.

I don't have grid. I'm completely off-grid. On a related note, I noticed today the batteries aren't charging at the same SOC. It looks like some of the batteries are charging between 60 and 80% (the 4th light is flashing out of 5), and some of the batteries are charging between 40 and 60% (the third light is flashing out of 5). So I am guessing some batteries never reach their proper SOC, which could be why the low voltage is an issue in the mornings, no?

This makes sense, as mine trips every time I switch on a high current device, like the kettle or the air fryer. Only happens in the mornings, once sun is shining it's not a problem. Can you perhaps share the settings you changed? I just want to contact my installer and have something to point him into the right direction. In my case it definitely looks like it's the batteries shutting down, and not the inverter. The inverter still reads "on", with the house just drawing 0W, so it looks like the batteries are shutting down. My problem is getting worse, though. At the start I could run the coffee machine and the kettle comfortably when I wake up. Now I need to carefully choose what I can switch on, and it's annoying as hell. EDIT: Sometimes it even switches off without the F56 error showing up on the inverter. It trips exactly like usual, and then switches on again exactly as usual, but there's no error on the error logger when I check.

I have the same issue. It wasn't an issue before, but now it chooses to rear it's head. Early mornings when I use a little bit of heating power (like switching on the kettle or dishwasher), the inverter gives the F56 fault and shuts down before restarting. My installation is a Deye 8kW inverter, with 4 x Dyness 5.12kWh BX51100 batteries installed. The batteries have a recommended 0.5C discharge rate, with a 1C max, so to me, it should never happen. I charge them slowly (way slower than their max charge rates), so that should also not be a problem. I'm off-grid, so it's not a grid problem either. To me, 0.5C on 4 x 5.12kWh batteries means I should be able to pull 10kW from the batteries in total, easily, but they're tripping when I get close to 3kW. It also doesn't happen all the time, only from time to time. I have a warranty on these things (they're not even 4 months old yet), but I need to troubleshoot myself before I get the installer out.

Saturday was a hot, sunny day, and we had a kid's party. That involved people camping on the grounds in a caravan with an AC, as well as a jumping castle thing. Because a lot of power was drawn the whole day, we actually produced more than 50kW during the day from the panels. Incredible!

As an update, today is Day 34 off grid. So far I've had blasting sunny days, and days with so much cloud cover it's hard to get the batteries to 100%. So far I've generated 1.06MWh, and I've had to use the generator only once. Only once because I chose to run it when cloud cover was thick, so I can get batteries a bit fuller before bedtime. I could have skipped it, but I figured the generator needs to run anyway, and "today's as good a day as any", so went with it. So far, I'm not sorry for a second. It's worth every single cent.

In the end I went with Jayceek Electrical: https://electrician.org.za/electricians/gauteng/pretoria/ess-jayceek-electrical-contractor-and-maintence-pty-ltd/

As is our usual habit, we use hot water once a day - at night, before bedtime. As such, I don't want a heat pump and all that, specially since gas geysers are coming down in price DRASTICALLY. This would be for when people come visit, or the once in a blue moon when we need hot water in the morning. That's it. On the flipside, it's rainy today (totally cloudy), but batts got to 100% no problem. Geyser is hot and water tanks are full. House now pulls 923W now on idle, with my PC running (working), as well as the big 24,000BTU air conditioner set to 21C in the living room. Inverter ACs are amazing.

I think I bumped it up to 30A charging. The batteries allow up to 75A charging, but recommend no more than 50A, so I think 30A is a good middle ground.

OK, so it's been a while, but we are off the grid since Friday late morning. I did end up going with: 8kW Deye inverter 4 x 5.12kW Dyness batteries 18 x JA Solar 545W Bifacial panels Install was done in a bit more than a day, setup took a few hours and then it was running smoothly. Eskom is switched off at the transformer, so that's all done as well. Absolutely no complaints, but I do have a few ideas. First, I'll need to address the water heating. We kept the electric geyser as-is with its 3kW element and it's fine. Switch it on at 08:00 in the morning, when there's enough sun to heat the water and charge the batteries, and run the house altogether, without a problem. The cloudy weather has been harder to manage, but we still easily get to 100% late morning with the water hot, house doing its things (coffee machine, kettle, etc. all running as well), as well as running the new ACs from time to time as needed. So that's not a problem. Problem is when we have a house full of people, and it's dark, and now the geyser is empty and cold. I need to get a small gas geyser installed just for the showers, because that's all we need. Hot showers at night, or early morning, is the only thing I can think of now that's actually required. It's not a NOW NOW thing though, it'll come in time. The second question I have is around the battery charging. To save the batteries, I have the inverter set to charge the batteries at around 20A each. It's just under half of what they can handle, and it works perfectly fine. What's odd is that the inverter charges the last 10% of the batteries at half power. I can immediately see the charge power drop from around 2.4kW down to around 1.1kW when the batteries hit 90%. Is that normal? I'd prefer if it charges a bit faster, specially the last bit, so I can use as much sunlight as I can, as soon as possible. I guess it's not a huge deal, but I just want to check if that's normal?

Yeah I've thought about it, but I'm not in the mood for that right now. The cost is a bit more, but yeah I would prefer the all together setup instead.

OK, latest update, my system was changed to the same inverter, 18 x 555W JA panels and 4 x Dyness batteries, for just under R169k. The problem now is getting the property on our names. In very short, the property was never changed to a smallholding when the original farm was subdivided. It's still registered as a farm, and farms can, by law, not be registered in two people's names. So this was a huge fight because the place is under 5Ha and in a municipal zone (so taxed at municipal rates). So registration hasn't even started. Friday we got news that this farm is exempt from that law though because it is under 5Ha and in a municipal zone, so we're hoping they'll hand in soon.