Kalahari Meerkat

Ok, I'll bite... Option 1 seems the correct one, but... if you are going to turn off the isolator manually, when T&L comes around and for the duration keep the panels disconnected from the inverter, then Option 2 seems like the betterer candidate, I reckon...

Ok, yes, but the 80V is not a problem, if you can provide 65A at 80V, then your MPPT should, provide, roughly 5200W at 50V to the battery, since the xxx/100 is limiting the battery end to 100A, this is also only 5kW app. max DC out, thus there's no point in thinking it an "upgrade", then only thing it will allow is higher PV voltages but therefore less current, like 20A or so, this will save on copper between the panels and the MPPT, but do nothing more, that I can think of. Basically the limitation is the xxx/100, he can add second one, if there more of a requirement for higher current on the 48V/battery side, but the 80V on solar panel end is not a limitation, only requires thicker cabling, since the current there would be higher than if he could run 200-odd volt instead... since he already has the 150/100, I'd assume the cabling from the solar panels is already appropriately sized and if he needs more panels, then more cabling is also implied...

Ok, I see 150Voc max for the panels and 100A max charge current, at 50-odd Volt, that would be 5kW... at 80V from the panels, you'd need to provide 65A, or thereabouts, so I am definitely not understanding the problem, other than providing 65A from the solar panel side would require quite a bit of copper cabling to cater for this current... what am I missing?

Ok, why? I would think the Victron 150/100 mppt feeds a 48-Volt-ish battery, so what would the problem be with 80V and higher Amperes?

This is not entirely accurate, if the 550 and the 330 have the same or very close to the same Isc and Imp, then you can happily series them... the lower of the current specs will be the limit of current flowing, thus a Voltage mix like this can work, but the current must be close to the same, else you would have larger losses...

Yes, in terms of current, but not percentage wise, hence it sitting at 15% and #4 at 16%, whilst #1 and 2 are still well above 20%, points to something else... I suspect the BMS does not decide what the Ah/capcity rating is for the cells, but it has been told what it is and that number is wrong, else surely the 100Ah number for #1,2&3 just seems too nice a number, it should possible be 94Ah, 100Ah and 85Ah, or so, for each of those 3 batteries, these are numbers I'm totally guessing/sucking out of my thumb, but the point remains, you state that the BMS should, based on discharge/charge data decide what the capacity of the battery bank is, but I seriously doubt this, I'm sure there is an entry on the BMS, where it has been told what the capacity of the battery is and this would not change, unless you actually update this with a more realistic/honest number.

Ok, I'm guessing you are running 3S4P with the 12 panels, you need to ideally confirm this, if that is the case and you get around 102V, then each panels seems to be around 34V and 12 in series (you'll have to re-wire again) would be 408V, which, I'd imagine should be fine and stay within limits for the new inverter. If, in fact its 4S3P, then the Voltage per panel would be 25.5V and 12 in series would be 306V, I think, which definitely is well within the limits by a huge margin for the new inverter. If the panels are 2S6P, I seriously doubt this, then each panel would be 51V, this seems way too high, so I can't think this is true, then 6S2P would be the setup for the new inverter, giving you 306V for 6 series panels. You will need to check what the current panel configuration is, I suspect 3S4P and 408V is likely the voltage that all 12 panels in series should then give you. Also assuming 34V per panel, if you want to be totally safe, then 6S2P should be 204V for the 6 series and that, again, would be totally fine for the new inverter.

well, if you have a decent multimeter you could probably just measure as your existing system runs during the day, your existing inverter is presumably still in place, what are its specs on the solar input side? you may find your 12 panels are running 4S3P or 3S4P, if your existing inverter is the 145V max on the solar side, I guess, but the you can still figure out the app. V per panel and decide whether 12S or 6S2P would be the correct option...

That should be fine, assuming the panels are Voc between 40 and 50V, then you should have 240 to 300V Voc and for Vmp, it should also fit for the specs of the inverter as for the 12 250W panels, you may need to split them into 6S2P, depending on their spacs, if they are also around 40V, let's say, then 12 in series would be 480V, which is probably not ideal, but at 240V (6 in series) should be find and the send set up 6 in parallel... EDIT: You really need to give the specs of the panels as well as that of the inverter, since my numbers above are thumbsuck and to get a realistic answer the specifications are needed, Vmp, Voc, Isc, then one can talk turkey as it were...

It could also be that battery #4 is actually not 100Ah, maybe, and hence it seems to deliver less power/seem to be the 1st to be near empty... I would still have assumed that all 4 battery banks should discharge at the same % rate, but that does not seem to happen, 22.6%... 24.7%... 15.0%... 16.6%... in this scenario even battery #3 seems dodgy...

Save it locally and open it with Google Earth, not sure if Google Earth web interface will read this as well... yes it does, so https://earth.google.com/ and then File -> Import KML / KMZ file

Bokpoort is Bokpoort CSP, there are 4 concentrated Salt Smelters around the Northern Cape, most of which have energy stored in the form of liquid salt, which is used to turn water into steam to run steam turbine generators each 100kW... as far as I can recall... see https://powerforum.co.za/topic/24552-commercial-solar-plants-around-south-africa/ for a little bit more information on commercial solar power plants around the countryside in SA.

Based on this there are plenty of (cheapskate) PV Solar plants, adding potentially 4-odd GWp of energy to the grid, but only around 0.4GW's worth of CSP that would still add juice after Sol has gone to bed... attached are the locations (Googely Earth) for the ones I've come across, maybe others can add to the collection... Solar power plants.kmz

Presumably stored energy from Bokpoort and others getting depleted overnight... it should increase during the day again, though, unless some so-and-so prayed for cloud cover here....

Yes, but what is this for? the TV Co-ax connector, presumably is on RG59 or similar coax and the RCA, heck usually on audio cable/thin coax.. either way, you will have to make up a linking cable, I have never seen an adapter for those tow different use plugs top be able to join.

That has absolutely no meaning, unless you are specifying the Ah rating you are looking at, I'm, sure someone can give you a 10Ah 36V pack that could do 2C, but I suspect it may not be what you are looking for...

Yes, well, quite a few kW's are going to the neighbour, since he has a grid connection still with a spinning wheel meter, but this *will* come to an end, he will cut the cord as well, since having this link for when it is cloudy has proven a waste of time... see my weather log entry for the 3d... 2023-11-03 Mostly clear initially, then cloudy by 13:40 and thunder & lightning with some rain by 14:15 a total of 4.5mm in the rain gauge by next morning... (rolling blackout from 14:06 to 16:05 then Eksdom shat itself from 16:47 until next morning 09:36 ) without enough battery capacity, of course, things stopped working around 03:00 or so, Saturday morning (BMS shut itself off... why did the inverter which should have shut itself down at 15%, or was it 10% not precede this? Fscking SunkenSynk, not the best, but between most of the bad options, not the worst either, I supposed...) Anyway Solar as seen below and also the grid Frequency to demo the Eishkom effect...

@WannabeSolarSparky forgot to specify, these are JA Solar 280W panels... in use since mid 2020...

Hardly ever seeing 100% from panels, but look at the following graph... this was yesterday and every electron possible was being used... some cloud here and there, but not too much luckily... (33k2Wh for the day in total produced) PV1 produced 14.4kWh for the day (9 X 280W panels looking north @around 45° tilt, I think) PV2 produced 18.7kWh for the day (8 X 280W panels either looking East at 45° elevation or more, at mid day at 90° elevation... looking straight up, or looking West at a 45° elevation or more) The north facing panels are seeing more shade early morning, as the sun comes further south of east, time too look at relocating these and also putting them on a north-south swivel to maximise production... Same graph for 2nd September, with no extension lead to the neighbour (Eishkom M.I.A.) between just after 0600 until just after 0800 as well as between just after 1400 until just after 1600... there also was some cloud cover here and there... (26k6Wh for the day in total produced)

No tumble drier, Kalahari sorts out wet washing, hang the washing outside, for an hour or so and presto... Stove, just a small unit probably peaking 1k5W, same for Microwave, induction cooker plate, evacuated tube solar hot water cylinder, which reminds me, I need to make an "afdakkie" for the hot water cylinder, the hot water is too hot... we can peak up to (on peak) get to 4kW when I run/start the electric lawnmower, but running, we're talking around 1kW for the Wolf lawmower. We tend to schedule things, want to run the dishwasher, no cooking until its heating cycles are over etc. if we had a larger than 5kW inverter, we probably would be more wasteful/less careful in scheduling. Spot on, although, even before solar, I was seeing that hey, running an Intel based server 24/7 as part of the household has some significant impact as part of the power consumption, we used to consume around 30+ kWh per day, which isn't huge, but certainly not a small number, nowadays, we're around the 17 to 23kWh mark, depending on cloud cover, we're more frugal, since solar won't necessarily cover us. Same here, we can and do exceed 10A on the consumption side, but that is always covered by solar... overnight, the consumption floats from an absolute high of 1k1W (Kalahari, remember, fridges & freezers) down to as low as 400-odd W, don't have aircon/heat pump, so a lot of moaning & bitching, when by mid day yesterday, the indoor temperature was at 30°C and walking out the kitchen door into the open air oven outside we had 41°C in the shade and climbing.

This sounds like a whole load of manure... 10A is 2k3W, we hardly ever consume this amount, which begs the question, why do they still roll the blackouts here? As it is, I'd be happy to see Eksdom close up shop, I can only equate them to the mafia, a total rip off and of course regime sanctioned...

Yup, that's what we do as well, also when the possibility exists for wanting a hot cup of something to drink at night (not this time of year), we'd boil the kettle (electrically) at 3PM or so an put the boiling water into thermos flask... no need to hit the battery to boil water at night... and here I am getting closer to cutting the extension lead from the neighbour, then we'll see how we do, but by then, I should have around 22kWh's worth of battery on tap and our daily usage is around that number day + night and during night is probably around half, 11 to 12kWh, which should be ok for us with the battery capacity we will have...

I doubt there are too many who sell back... maybe if there are any on the forum, they can let us know how its going and where they are located (which Province/Municipality). Everyone got all fired up about being able to sell to the grid and initially in America, Australia and Europe it looked great, for a while, then problems showed up and invariably, the production curve for solar means everyone with solar has excess from late morning until mid afternoon, possibly, but that is not when consumption would peak, I'd think and thus in Europe, you get practically nothing for you electrons during peak solar production and you have crafty fellers that can afford to invest in *LARGE* battery banks, wanting to charge when it costs next to nothing and discharge this back to the grid when electrons are priced at a premium... In various parts of America they don't want to take the feed into the grid anymore, its more effort and trouble than what its worth... I suspect even in South Africa, this will be a short lived scenario, best move is to cut the cord if you can and put the savings into a separate savings account to fund future solar replacement/expansion outlays.

Ok, which one has the 35mm^2 cable? The cells are not all that nicely balanced... Pack #1 52mV between lowest and highest cell Pack #2 31mV between lowest and highest cell a bit better than #1 Pack #3 seems to have larger divergence based on the average and highest Pack #4 seems to have the best balance, I'm guessing based on highest and average... If they are all in parallel, I would have expected Pack #3 to provide more current than any of the other individual 3, how long are your cables between each battery and the busbar? Why are #3 and #4 both delivering significantly less current that #1 and #2, when #3 should be current king... where is the takeoff on the busbar toward the inverter, closest to #2 perhaps? followed by #1 then #3 and finally #4 possibly? Based on the BMS cycles #1 and #2 have done 43 cycles and #4 40 and #3 only 5 so far, but that is the cycle count from the BMS since its count was reset, it could have done many more and the cells certainly probably many more yet, presumably in a different setup with a different BMS. All you can do is see that you have as low a resistance as possible along every link of this DC chain. 35mm^2 cable is rated for over 100A, so yes, it probably has a little bit more resistance than the 50mm^2 cables, a longer length, of course, will have a more noticeable impact yet, but since the battery to which the 35mm^2 cable is connected, is a 100A current rated battery, the cable should be fine, but ideally the cables for all 3 100A batteries should be the same length and diameter and the 200A battery should also have the same length but double the diameter, to balance things out as well as possible.

I don't think this will work out quite as well as everyone hopes... if there was excess generating capacity when its needed, but the rolling blackouts have been in darkness recently, here, at least and that's when Eksdom and City power would be welcoming feed-in... so, if you have excessive battery capacity and can feed in, at those times, then let the good times roll... but I suspect not...