Derek Ramos

Yes this helps, thank you for the explanation

@Sc00bsI’m a little confused by this, I thought that you had to stick by the Voc of the panel combined by the number of panels to give you a total volatage. So the 8kw sunsynk has a max DC input voltage of 500v per mppt. So I can fit 10x 545watt panels at a 49,52voc to make 495,2v Per mppt. Is this correct? I checked some 455watt panels and it seems the Voc is almost the same as the 545watt. Won’t this damage your inverter. Assuming you have 14 panels per string at 49voc then that would give you 686v.

I’m busy price checking batteries an it seems that the dyness battery is far cheaper than the rest of the batteries in a certain range. I’ve seen quite a lot of people using dyness but why are they much cheaper? Are they poor in quality or just full of problems. I would be using 2-300ah on an 8kw sunsynk.

@jumperso what you saying is that its not a good idea to expand your battery bank. That would seem to be a problem for most people that start off small because of finances and later add to the system.

Thank you all for your comments

So most people on the forum speak about JA and Canadian solar panels. I have seen that some people use Jinko. Because I’m still new to all of this I wanted to know if Jinko is a trustworthy panel? Is it a good brand. The price from solar and inverter warehouse is the best currently for a 545watt panel, But because a lot of people use JA panels I’m abit hesitant. I’ll be using about 18panels on a 8kw sunsynk, 9 x panels per string on one mppt and 9 panels on the second mppt (east- west orientation) Jinko 545watt 49.52v Voc anyone that uses them or knows more than me about panels, your input would be greatly appreciated.

Great, thank you..

Thanks for this… it’s still slightly difficult for me to read.. what does it mean with the graph pointing downwards (purple) but I can see that there is a massive difference with your eskom power usage. That’s great! I’d be very happy with that my 8kw sunsynk arrived yesterday, lol but I have nothing else😂 it’s still going to be a few weeks before everything is up and running. how many KWH do you use everyday on average? I currently use between 30-35kwh but this is winter. And I run my geyser from 5pm-8pm in the evening, at 9am my geyser water is cold! It’s crazy that it doesn’t hold the heat that well!

Thanks for the comment, problem here is I leave my house at 7.30 so I need to switch my dishwasher on before I leave. You see when my wife cooks she likes to use every piece of cutlery we own so it’s a must that I run my dishwasher at that time. battery charging will come after the dishwasher finishes at about 10.30 and geyser will start once the batteries are charged. This is the only solution right now but I will see once every is set up for a few weeks and maybe adjust some times.

I’ve just gone through this whole exercise on what inverter, batteries, panels , geyser timing and so on. I also have a crypto mining rig. bottom line is that this doesn’t need to be done all at once, I would rather get the right inverter and battery or batteries first and set yourself up for load shedding. You in the meantime can get your electrical in house sorted out for essentials and non essentials and then as you get more funds start adding one panel at a time until you get to the point that you have enough panels. for me, the sunsynk was a no brainer, most people use them and almost everyone suggested you should use them. There’s obviously a lot of reasons why… if you do this exercise correctly then you only going to do it once, if you get inferior products you might be redoing your whole installation twice. At the end of the day it’s all up to you but just do it right the first time even if it takes you longer to complete rather than wasting money. eg, my 8kw sunsynk arrived yesterday, super excited but I have nothing else. I haven’t decided on what batteries yet but I was 100% sure of the sunsynk, that’s why I’ve already bought it.

Do you have a graphs like this to show exactly how much kw you use in a day? Essentials and non essentials, and then exactly how much kw was used from solar, batteries and eskom. for a full 24hr day. I’m interested to see how many KWh you use in a day and how much you save with your equipment

@WannabeSolarSparkyYour geyser is pretty efficient, what temp do you run at? if I use 1000watts for 3 hours a day with solar on my geyser it will save me R250 month. Small amount of money but in the long run it’s a win for me!

They don’t need to match, 9 on mppt 1 and 5 on mppt 2 is fine. It obviously wont be the same amount of wattage but once they come into the inverter the wattage is combined

Thank you

@Scorp007Thanks so much so just making sure it is possible to install 9x 540watt on one string per mppt at a Voc of 49.6v. Making a total of 18 panels without causing potential damage to the inverter

Hi, read through this post because My 8kw sunsynk will arrive in a few days. Trying to work out the maximum amount of panels I can use and this post was very helpful, just a quick question, the max dc input voltage is 500v and on the 8kw sunsynk spec sheet it states the mppt range 125v- 425v, now is this figure per mppt or for both mppts together. you mentioned that 9x 540watt panels will be okay on one string on one mppt, but can you add another 9 x 540watt panels on the 2nd mppt. 9 panels east facing and 9 west facing. if this is possible then won’t it exceed the maximum dc input voltage of 500v if all your panels are almost producing max wattage at mid day?

I haven’t completely figured out which batteries but I am thinking at least 300ah to start. 😅this is becoming a very expensive exercise but no going back now, my inverter is ready for collection 😀

Just to let you know what I’m thinking and also it’s good to write it down so it makes sense (for myself 😂) i run my dishwasher every morning from around 7:30am. It draws about 1900watts periodically for 2hrs. So I’d set my inverter to use solar on my non essential loads first and then the balance to charge my batteries and run my rig (essentials), once my dishwasher is done I don’t have any load at my house from 10am until 4-5pm besides my fridge(max 135watts) and rig (700watts) I’ll monitor this and possibly make changes in the first few weeks. Once my batteries are charged I’ll switch on my geyser with the sonoff, might need 2hrs here but I’ll also look at insulating my geyser. I’ll need a sonoff for my rig as well, I’ve got a plan in theory but I’ll have to test it, I’ll run the rigs sonoff ac out through a contactor with A1 of the contactor connected just before the ct coil, so if load shedding occurs at night with no solar it will pull the contactor out (no ac power on essentials) stopping the power flow to the rig, but if there is load shedding with enough solar during the day then my rig will stay on through the contactor and run on solar until there is no solar left and the contactor will pull out again. Does this make sense to you or am I doing it wrong 😂 I’m tired so my theory might be BS at this point. given the rating of the 8kw inverter I think I can only fit 9 x 540watt panels on one string on mppt 1, so if budget allows I’ll add 9 panels on the east side of my house to get as much solar in as possible in the morning for my dishwasher and rig and batteries. Then depending on budget ideally I would use another 9 x 540 watts on the west side on mppt 2 to accommodate the geyser and rig load before the sun goes down. I’m still unsure about this because they say the mppt has a voltage range of 125v- 425v but I’m not sure if that is for both mppts together or each mppt has that voltage range separately. If it’s separate then I can definitely do 9 panels per mppt. anyway this is just what I’m thinking about, But your posts have been very helpful.

@WannabeSolarSparkythis is fantastic information, I got 90% of all my answers with your posts, and because I’ve been watching the sunsynk videos I understand a lot of what you saying, so thank you very much. I won’t be able to control everything exactly like you do because I don’t have a raspberry but this has given me a lot of ideas on getting things done more efficiently. I own a commercial refrigeration business with my family an we constantly use contactors , timers, controllers, relays an so fourth, so I’ll be able to incorporate some of this to switch the rig off during load shedding. I think I’m going to start building my electrical boards, I’ll figure it out as I go. I’ll get one of these sonoff controllers to monitor my geyser and also use it as a timer, I’m assuming you have this happen once your battery hits a certain percentage, then powers off the rig and allows your batteries to run the house.

Sorry I’m back on the geyser thing, you only run your geyser for one hour, how many watts is your heater element and I’m sure one hour is not enough to heat up the geyser? Also looking at your product from your panels you don’t really have enough wattage from your panels to supply the geyser so this probably takes some power from the grid?

@WannabeSolarSparky so your crypto takes the first 750 watts from the panels and then what’s left over charges your battery and supplies your house and once your battery is at 100soc then it supplies power to your geyser on your selected time( in a nut shell) but what happens during load shedding? If your crypto is the only thing on your essentials then when load shedding hits you don’t have battery power going to your house?

On this graph, the blue on the top line is the power you’ve bought from eskom? Green is? Red is your geyser and stove? Yellow is your house and miner? Sorry for my ignorance as I’m not so clued up with the abbreviations

So the 4 panels facing East has enough voltage to start your solar input in order to charge your batteries, then the 6 panels facing west allows you to get more solar in from around 12pm to start powering up your geyser so you have more watts coming for the higher demand? And with 4 panels you have enough wattage to charge your batteries to 100% by 12pm?

@WannabeSolarSparkyso your essential side of your house runs on solar during the day and then only starts using your batteries when there isn’t enough solar? So on a very bad rainy day then your batteries will charge from the grid but when they have charge then your essential side will constantly be running on your batteries? Or if you don’t have your batteries charged it will run off the grid until the batteries are charged. Thank you for this, I have made it a point to watch every one of these videos to gather as much knowledge as possible

So your geyser only takes 1 hour to heat up but also you saying that it uses excess solar and and some power from your grid, in other words your 10 panels don’t supply enough solar to run your geyser.. it’s a little worrying for me as I’m also going for 10 panels but my geyser takes 2-3hours from cold to heat up to about 55 degrees. Besides my crypto miner, my geyser uses at least 70% of my electricity bill. (3600watts) my geyser running on solar is going to be my real money saver. New panel setup? 5 East and 5 west? Or did you change something. My panels will also be East and west as I have no north facing roof space. This is with your raspberry pi ? Lol I had a look at that, way to advanced for me and I know nothing about that, I might have to pay someone 😂