Don

No, the amps only determine how long it takes to charge your battery to reach your bulk charge voltage and then float charge voltage. The lower the amps, the longer it will take to charge. If you want to limit the SOC, you need to reduce the bulk charge voltage and float voltage, not the charging amps. The amps is the rate at which you charge the battery. You can charge a battery to 100% SOC at 2A, it might just take a few days.

My float settings for my 2 x UP5000 batteries are 51.9V. My bulk charge voltage setting is 52.5V. At 51.8V my one battery only goes to 99% SOC. At 51.9V both go up to 100%. Yes, I am sure you can limit the SOC with the charge voltage setting. If you for example only charge the battery to say 51.2V, the SOC will only go up to say 90%. You will have to increase the charge voltage to get it to 100%.

68 kWh daily power requirement of which 34 kWh is required for geysers. You have a geyser problem. You need to reduce your daily power consumption. Option 1 is a no-brainer. @Quintrixand @YellowTapemeasurehave mentioned the most important things to have a look at. Once you have done everything you can to reduce your daily power consumption, then do you look at what you can run during the day, i.e. schedule your geysers to heat up one after the other. You might decide to keep the oven and aircons, (if you have them) on the grid or non-essential loads side. Then only can you determine what size inverter, batteries and solar panels you require for your system.

100%. The battery determines what load or charge it requires, not the inverter. The inverter is able to supply 80 amps charge to a battery on demand. If you connect a fully charged battery to the inverter, it will draw 0 amps from the inverter. Pylontech batteries have built in BMS to protect the battery from overcharging it.

It is a joke. People that make statements like that obviously did not have mathematics or economics at school. The problem is Eskom is running expensive diesel-powered open-cycle gas turbines (OCGTs) that were designed to do maintenance with and run 3-4 hours a day in an emergency to generate power. Today these units is form an integral part of the grid and deliver as much as 30% of the power requirements. It is madness. Ask any guy running a generator petrol or diesel general what it is costing him to run a generator. The cost is killing them. "At that time, it was around ten times more than buying renewable electricity per kWh." Therefore, they want to blame the guys running on solar for the high demand and make them pay 10 times more for power? It is like pointing a double barrel shotgun at your foot and pulling the trigger and hope it will be fine. "Eskom currently relies on OCGTs to supplement its generation during peak hours." - Why? Because they have not done any planning. Koeberg license is expiring in 2024 after 40 years of service and they are supposed to shut down. Do you think they will shut down? No, they will probably extend the license for another 20 years. Another Chernobyl accident waiting to happen. Coal fired generators are under pressure to shut down due to high emission rates. Will they shut them down - No. Why do I say they will never shut down these power stations and run them into the ground until they self destruct. It takes 10 years to build a power station. Eskom, can you please show me what you have planned to replace Koeberg and al the coal powered power stations, seeing that these new power stations should be coming online shortly to power SA into the future - I don't expect an answer soon.

At 4.5 hours your your load was around 1000W. That is the capacity of your battery to draw it down to approximately to 20% SOC. If you need more than that, you need to add some more batteries. Looking at you base load, you need at least another 2 batteries for 12 hours of backup power. If you run an aircon in a room from batteries, you probably need another 3 batteries for 12 hours backup power. It all depends on how much backup time you require.

Yes, you have a very high base load of 1.5kW - 2kW while everyone is asleep. That is a lot of power. Are you running aircons off the inverter as well?

I am not sure why we are still debating this? 1.) If you connect all the neutrals together, the earth leakage will most likely trip. 2.) It is against the law.

I installed a new system in December 2021 with 2 x 5000 Pylontech batteries. Afterwards I noticed everyone making use of Hubble. Lately, I have seen a few negative comments of cells failing and batteries being exchange at a high rate, not to mention the cycle counter running in turbo mode. I know my system is still new, but I must say the values I get from those batteries looks like a mirror image.

Yes, keep the neutral for the essential load separate from the non-essentials.

I see their price have increased as well (R170) per panel on the 540W panels, but they are still the cheapest by far in town. I just received a call from Geoty. Truecaller identified the number belongs to "Land Works Africa Ta Geoty Resources". The guy was very apologetic as they were supposed to deliver my panels today. He said they have a backlog of orders and ran out of stock at their warehouse and had to get stock from their other branch in Cape Town and will only be available early next week. Obviously I was not very impressed. He said if it is unacceptable to me, they would give me a refund if I am not willing to wait. I don't want a refund. Then I have to order it from somewhere else and probably pay R5000 more for the same panels. I said it is fine, I will wait. He sent me a new invoice, reflecting the new delivery date as 28 January 2022. I told him I need another 4, but they will force me to get it somewhere else. He said once they deliver the panels next week, we can discuss the next order. I guess we all have to wait another week. Personally, I am not concerned, I am confident I will receive the panels.

If you install it above the DB board, there is a risk of drilling into live cables trying to install the inverter as you normally have many conduit pipes with live wires running from the DB board into the roof area.

I was also sceptical, but as you said, I also saw stock moving and delivery dates continuously moving forward, so I decided to take a chance and order panels from them. I will be able to confirm soon, as my delivery date is tomorrow.

SOLD

Yes, sure. I will go get it and take some pics.

@LoodPyp, you summed it up perfectly. I think most of us start of with a). Then we add a few panels to achieve b). Then we start pushing the limits and add a few batteries to achieve c). That eats deep hole into your wallet. As @Scubaduderightly said, d) is "Costly and sometimes unobtainable goal." I think once you have reached that goal and look back and wonder if it was worth spending all that money, as the ROI of probably 6-8 years (just taking a wild guess here). We would all like to go off-grid. It all comes down to how much money you have available to spend and what sacrifices you are willing to make. I also believe a lot of guys sitting at c) that think they can easily cross over to d). The day we have a "Blackout" and the grid goes down for 2-4 weeks (not to far into the future), they will have a rude awakening as that will be the ultimate stress test when they realise what it really takes to be off grid.

Item: MECER 3000VA/2400W INVERTER Age: Approximately 4 years Price: R2000 Payment Method Accepted: EFT Warranty: No Packaging: No Condition: 100% working condition Location: Limpopo Reason: Upgraded to 5kW Inverter Shipping: Yes, for buyers account Collection: Yes Mecer 3000VA 2400W Specifications.pdf

If it was only tea time cycling, it would probably not be a concern. The problem is it happens many times a day, depending on load and cloud conditions. Like the time when the guy did some welding and the power tripped 10 -15 times. These are all unplanned events, but they happen. You mention on some days the sun sets and the batteries are not fully charged. Then you run the batteries until 21h00 when they eventually switches back to utility. You cannot drain those batteries every day and expect them to last. You mentioned that once you have a sudden increase in load, the batteries used to carry the load, now the inverter goes to utility for 10 minutes. It is because the batteries are no longer able to handle the load. The inverter then bypasses the batteries and goes to grid. Over a period of 1.5 years you have killed the batteries. Lead acid batteries were designed to handle a sudden high demand for power (high amps) over a short period of time (seconds), i.e. starting a car or engine. They were not designed to draw power from over extended periods for hours at a time. It just kills them. Don't worry, I had 8 x BSB 250 Ah Solar Batteries. Massive batteries, 73 kg each. Design life span was 5 years. When I got them, I could run my house for 2 days on them without solar. A year and a half later, I was lucky if I got 4-6 hours out of them. I have got the t-shirt, they don't last and I don't want them for free.

@Green Power1.) Fist of all, lead acid batteries, gel batteries, deep discharge batteries, whatever you want to call them is not suitable for solar applications in my view. If you discharge them below 70% SOC, you damage them and they will not last. Yes, they are cheaper than lithium iron batteries, but they are useless. Don't waste your money, get a lithium iron or LiFePO4 battery. You can probably discharge them to 20% SOC without damaging them and get about 6000 cycles out of them. 2.) You need an inverter that can run on solar and if a cloud moves before the sun, to use grid power to make up the deficit. Your Axpert MKS II 5kW is making use of battery power to make up the deficit. You are continuously cycling your batteries, they are so confused they don't know if they are charging or discharging. The batteries will never last. 3.) Batteries are expensive and you don't want to hammer them each day with high loads and reduce their life expectancy. Yes, we all want to get our money back from what we paid for them. Rather switch over to batteries at say 21h00 or 22h00 at night when the load is relatively low and constant to run until the sun rises the next morning to charge them again. To run of batteries during the day when the wife switches on the kettle every 30 minutes while doing the ironing and heating up yesterdays leftovers in the microwave while the tumble dryer is running, is a battery killer. I admire you for trying to save the world and paying for it out of your own pocket, but for now, first get the right system in place that works for you , you can save the world later.

Batteries don't like extreme cold or hot environments. That is very cold for a battery. The battery might deteriorate faster than normal. Ideal battery operating temperatures are between 15 and 35 °C.

Thanks @Coulomb. That makes sense to me now. Although it shows bypass, it is actually a mixture of utility and solar. Therefore, in Usb mode it will always show bypass, although it might be 99% solar and only 1% utility.

After batteries were recharged, the inverter showed that it was in Bypass mode, however if you look at the Power from Utility = 0 and the load is supplied from Solar only. Not sure how that works?

@DirkieI disconnected utility and ran on batteries with high load to draw them down to 90% SOC. When I switched utility back on, batteries were charging from grid and solar at the same time.