Wilfred

What is the worst that can happen? Let’s say I brick an inverter, will it need a new pc board or something, or do I have to throw it in the dustbin?

Thank you both @Coulomb and @Youda. I will push for them to come and do the firmware update.

@Coulomb and @Youda Just for interest sake, maybe you guys know, I am no electrician or IT person. Is it possible to use a network hub, have the cable go to the hub from the main battery and from the hub take it to each of the inverters in parallel? Is this a possible solution? This is for the communication cable and for the use of the PYL setting on both inverters.

Great, thank you for looking into this. I am close to having my firmware updated, I am waiting on an “Engineer” at the supplier to come and do the firmware update, then it is their risk not mine hopefully we can get this done soon, I am looking forward to have both machines interact with the BMS and display the same correct info as supplied from the batteries.

I don’t know how much load your aircons will draw (mine need a service and it is the one thing I have no idea what the load will be, we are not using it that much). I would definitely, to increase the life of the batteries, also move the oven over to the grid directly. We have about 4x roof fans running through the night, they are not making much of a difference in our night time load. The microwave is so quickly, don’t think it should be an issue.

I see the system working like an old school turbo charged car with lots of turbo lag. Even if your inverter can do something like a 5 000w constant draw with a 10 000w spike, it would trip before it can even deliver that if your battery bank is sized too low. The inverter need to supply the power you are asking from somewhere, it want to get it from the PV, but the PV’s and inverter has lag (turbo lag if you will), so first it will get it from the batteries, if the batteries can’t supply it, “CLICK”, self induced load shedding, reset everything, let’s try again.... rinse repeat.

Even simpler math. R52 000 / 2250 cycles = R23.11 per cycle (omni batteries) R58 000 / 3 600 cycles = R16.11 per cycle (pylon batteries), if you could only get 3 600 cycles out of them (1 cycle per day for 10 years)

A supplier will sell you what he have in stock and that stock will be the best you can buy for your money, otherwise he is not a good salesman, weather it is a lithium-ion or a lead acid battery. I have seen it when they wanted to sell those lead acid batteries to me and they don't believe in lithium-ion batteries. But let's get real, lithium have much more advantages than lead acid. Some are as you mentioned, the use of space, the DOD, etc. I believe over the long run lithium batteries cost less than lead acid, plus some other advantages like adding another battery later on, how much later I don't know. It seems that Gel/lead acid/flooded batteries last an avg of 4 years, I was quoted a bank of 9.6kWh in the region of R61k (can't remember if this was VAT incl or excl) with only half of it usable, at that stage for a similar amount of kWh storage the lithiums even came out a bit cheaper PER kWh, but on paper the lithiums won as it has so many more advantages than the "old" technology, yes there is a difference between 50 AH, 74AH, 100AH and 200AH, etc. From what I have tried to accumulate between the pro's and con's between the two, I can not imagine that Gel/flooded/lead acid batteries can be fun to have with all of the maintenance. My cycles, and I am running off-grid as much as possible, is turning on average at around 0.75 cycle per day. I am sure the bigger your bank is with lithiums as well as other batteries the slower your cycles will turn. My batteries are most times at 100% in the afternoon and at the lowest point it ever reached once was 21%, most of the times the lowest point is 22%, recently it barely went down to 30%. Weather you have lithium or other batteries, they need to be looked after to get the lifespan out of them. Let's say I will get 6 000 cycles out of them (I don't really think so as we run higher temperatures than the sheet state (25 degrees), and let's say I paid R70 000 for 4x bricks, let us imagine that I use 14kWh per day. 6 000 x 14 = 84 000kWh used. R70 000/ 84 000kWh = R0,8333 per kWh used, is there something wrong with my math? You pay upfront R70 000/14 = R5 000 per kWh storage, but the storage can be used 6 000 times. Or, 14 x 80% (DOD) = 11.2kWh usable. 6 000 x 11.2 = 67 200. R70 000 / 67 200 = R1.0416. This is the amount I pay for the use of my Pylontechs, cost per kW. I don't pay the city council anymore (around R2.20 per kW) for the use of this power as it is generated by the sun. I just tried to take into account what these bricks are costing you over time and the usage over the time. Yes the SOH will decline over time and I think at 60% SOH they are done. I have no idea when the SOH will start to decline. If they will only last 8 years, then you have 8 x 365 cycles = 2920 cycles (close to lead acid with their 2 000 cycles, but they don't last 8 years). 2 920 cycles x 11.2 kWh = 32 704kWh. R70 000 / 32 704 = R2.14 per kWh, it is still cheaper than Eskom charges and you will not have an annual increase like Eskom. Is this making more sense? Then on the other hand with the smaller kWh storage in lead acids, and the calculation above, I can now understand why most lead acid batteries only last 4 years, they probably turn two cycles a day. Now, you have a warranty for 10 years, lets take 10 years and a simpler calculation and hope that these batteries will last 10 years at least. R70 000 / 10 years = R7 000 per year. R7 000 / 12 months = R583,33 per month. R583,33 / 30.42 (avg day per month) = R19,18 per day. R19,18 / 11.2kWh = R1.7125 per kWh used. My city council charge me R2.20 per kWh currently. I guess the same sort of calculation should be made with other type of batteries. In my opinion lithium batteries are cheaper in the long run than other type of batteries, I don't have the experience with gel/flooded/lead acid to prove myself wrong. But it just seems that lithium batteries are more cost effective over it's lifetime than other type of batteries. We are running the batteries at a higher temperature, I guess in winter time they will run at a lower temperature, I am in no way an electrician and don't know how exactly this will influence the cycles but lets say you have a 40% loss in cycles, then you should still at least get 3 600 cycles out of them. 3 600 / 365 = 9.86 years. It might still be cheaper than city council prices per kWh used. Maybe, like some technology has done in the past, it will become cheaper as we are going forward, hopefully the same thing happens with lithium-ion technology. @viceroy If you are committed to 3x US3000's, I wont even downscale if I were you. Just replace the battery bank lol.

Plenty information on the data sheet, to understand it all is another story. Yes, @plonkster have a very good understanding of batteries, I am still learning. Luckily my power usage at night time will barely go over 1500W, but with 4x of those batteries I don't even worry about it. Most times my batteries end up without PV @100% SoC, the lowest it went down to was around 22% then the PV kicks in, I only had one instance when the AC kicked in in the last 44 days of use. I have pushed the system to 6000W around three times and never had an issue thus far, no alarms, no shut down, system works perfect with these batteries. I like that I am learning a lot in a field outside of my expertise and I like to play around with these things to see what happens and when it happens.

I can at least tell you that USE is for lithium-ion batteries, you have to use the AGM/Flooded setting, I don't however know which one of the two, I am a lithium-ion user and this is my 1st experience with renewable energy stuff I am aware of the battery EQ program but have no idea how to use it. Also have no knowledge regarding the charge settings on the gel/flooded batteries.

Out of those three, I only know the Pylon's, in my opinion they are working well. I am sure that they are compatible with Victron and Goodwe.

Hi, You can run basically anything from solar/solar system. It just have a trick to it. 5KW inverter can only handle max loads of 5KW at a time, with a boost of couple of seconds. You need to figure out how that 40kWh is distributed during the day. You also need to figure out how much you are using maximum at a time. If you push more than 5kWh with a couple things on, a 5kW will not be enough. Your battery bank need to be sized to be able to handle the kW usage (inrush) until something like the PV can generate enough to take over the load. In your scenario where you will use it as a back-up system for load shedding, 2x US3000's should be enough (as you only need to handle 2.5hrs of darkness currently), but you have to limit loads at that same time to lenghten the time, as well as to compensate for what the batteries can handle as Plonkster pointed out. Typically a new US3000 will each give you around 3.2kWh, meaning you can use 3.2kW per hour, if you draw a constant of 3kW it will only last one hour. If you draw 1000W per hour it should last 3 hours, etc. As I was typing this @plonkster posted

My last actual reading was taken end April, water was read every month but not the electricity, I declared my readings last month online and will do the same this month.

Basically you are looking for software? https://iccsoftware.co.za/ There are other software as well out there, should be able to find it online. If you received watchpower on a CD with your inverters, I know that you can install it on a Linux OS (Rasp Pi). I just can’t get it working, it might be that I plugged it into the wrong port or something. https://answers.informer.com/161657/watchpower-on-raspberry-pi-3

How many batteries do you intend to install?

The cost more or less of the US3000 Pylontech come to around roughly R0.8333 per kWh used over it's lifetime, which in turn is roughly 1/3 of the current cost you (in my case) currently pay your municipality. A solar system is expensive to get it installed and up and running, after that, you should push everything you save on your electricity bill into a fund for your next repair/replacement, or even in your bond. Then again, take a plot of land with no services, it would cost you roughly R175k up front to get power connected, after that you pay for usage. For the same money you can get solar system installed and start expanding later. No monthly usage cost.

Thank you, I am trying to get my two inverters to communicate correctly with each other when linking the battery cable

Thanks, I can confirm that it works with the cable as described here @9600 baud. When inverter set to 05="PYL" running firmware version 71.80. (It did not work as 05= "USE" but worked after changing to "PYL"). Excellent, It will only work when set to PYL. One question? One or two inverters? I have FW 71.70 and it works as well.

Very odd, double checked all settings? Usually when these inverters go nuts, the only thing if any that happens is that the batteries charge either from grid or PV or both. Had an incident at a client of mine where the inverters went into bypass mode, no idea why, me and the owner got two of the inverters out of it but not the 3rd inverter, single phase, the inverters used grid and PV and could not get it off-grid. I told him to switch the system off totally and restart it, I don’t know if he did it.

They are already pissed off at me as I made them correct my meter readings, send someone out in the beginning of October already and never corrected my readings then I sent my readings in, system had big red letters going as the meter reading and the estimated reading was too far apart, then I uploaded photos and it was corrected, will see when they send another inspector out.

I had some custom made and slapped it in my meter box

What are your settings currently? The only setting to charge from Utility that you can change that makes a difference is setting 11. what loads are running while you want to charge batteries? Do you have something that tell you how full the batteries are charged?

Do anyone of you buy the statement that there were “sabotage” which caused the load shedding? I would rather say that someone was incompetent. I really recommend that these guys should watch the series called Chernobyl, can’t believe they want to look at nuclear energy when they can’t even manage something as safe as coal driven energy. Also that Zimbabwe had an illegal connection for the past 15 years which was found when Eskom were contacted by Zimbabwe to sort out their supply after the recent load shedding? Apparently they could not account for R2 billion worth of electricity that are missing per year, I don’t think all of it went to Zimbabwe though, but R2 billion worth of illegal connections, which the paying customers are charged for in the end.

What is the best course of action here? Run the system on USB until the rain stops, keep them batteries full? I am trying to find a schedule so I can reset my geyserwise as I am not always at home/office to keep an eye on things. Eskom reverted back to stage 4 since 22:00.

Congratulations, I guess the process will speed up for all the other applications now that Eskom is into the deep end. Not that it is enough to safe them.