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___ last won the day on September 13

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  1. In my house we generally have two cars. The one is the long distance holiday car, generally dad's car. It is bigger, more comfortable, and it has an internal combustion engine because it needs to drive deep into Namibia. The other one is a small little hatch that does maybe 6000km a year. We bought the last one 5 years ago at 85k. Right now we're kinda sorta thinking of maybe replacing it, and the budget is 150k (ish). An EV would be perfect for this second car. But for the difference in price I can buy a heck of a lot of fuel and do a lot of maintenance... and get some interest on the difference. An EV is perfect for the man who lives in the suburbs and works in the CBD. He drives every day, and the mileage is perfect for even a small EV. He will likely get his money back rather soon. However, COVID19 has taught us that we can work from home and completely skip all that nonsense...
  2. Oh man do I have a story. Well two... When I was about early high-school years, my dad sent me to go fetch the Bobbejaan (for those who don't know, this Afrikaans also means Baboon). My younger sister (probably around 6 at that time) who was inside the house heard this, and came out of the house, waiting anxiously for my return from the storage place, which was around 100 meters away. She was quite upset when I didn't return with the expected Baboon by my side, but instead with a monkey wrench. The second was a case that almost turned into labour unrest. My dad and his employees were putting up a water tank. The tank was tied down with a rope, to prevent the wind from doing any bad things. One of the workers untied the rope at one point, and my dad shouted at him (as one does), don't untie that rope you stupid! Well, no, in Afrikaans we call a stupid person a Bobbejaan, so that is what he said, and as many saffers know... that can also be construed as a racial slur. The worker replied "Ek is nie Bojaan nie!", and then proceeded to sulk for the rest of the afternoon. Count your words as they say!
  3. Waterpomptang! Growing up on the farm my father would say that that funny-looking pliers isn't really useful for anything, and I remember that there was one in the toolbox which we almost never used. We'd always go for the monkey wrenches. Of course everything was 3/4" steel pipe... or 1.5" black pipe. Then I moved to the city, and I learned that plumbers use essentially just a water pump wrench and a maybe a shifting spanner. Occasionally a blow torch... As a result, I now own both good water pump pliers and two monkey wrenches, and I almost never use the wrenches anymore
  4. I edited my original post because I got the math wrong. 5*70 = 350Ah. At 10kW or 200A, that is a little over C/2. Which should not be an issue for an LFP cell. So 2 (extra, in addition to the 3 existing ones) will do it, but 3 is better. During testing, I've never seen a Pylontech battery raise a high current alarm... but that may just be because we haven't done it long enough. Hence, I don't know when it raises such an alarm. Other batteries I've worked with tend to allow you some abuse as long as they remain cool, below 40°C.
  5. Sure... but the question doesn't have a yes/no answer. It has a "how long" answer. I don't know. As long as the battery stays under 40°C and you stay under 2C discharge rates. 10kW is 200A. A US3000 has a 70Ah capacity iirc, so 280A is 2C. Remember also that the Pylontech batteries keep a log of what you do with them. As in literally... it has event data in it. If there is a warranty claim, they will pull that data down and see what you've done. Personally, I'd advise doing 2C discharges for no more than maybe 60 seconds. So in my mind, though a 10kVA will run fine, you won't be able to actually use the whole capacity of the inverter. a 5kVA is better matched, or double-up on the battery. Edit: I made a math mistake. You said you had 3 of the racks. That's 200Ah, so a 10kW discharge is 1C. The battery can handle that for as long as it remains cool enough. It exceeds the recommended 0.5C discharge though, and as I said, the batteries log it.
  6. A Quattro is just a Multi with two AC inputs. The inverter component is the same as for the equivalently-sized Multi. So your Multi-knowledge will be applicable in most cases
  7. I mentioned that there are over 1000 different "brands" of pianos, the analogy is that it is the same for batteries
  8. Müller was a bit like a furniture store back in the 1900s in Cape Town. If my google-fu has not left me, the remains of that company is still around via Allen and Fisher pianos, who still have premises in Wynberg today. They imported pianos from Germany and sold them under their "house brand". That is why many of these pianos are basically either an Otto Bach or a Carl/Carol Otto under the skin. Some of them are quite good. Others (like mine) look the part but are basically workhorses underneath. After buying such a piano without doing any of the required research (and almost ending up with a dud, but we saved it), I did the work afterwards. That's when you discover how the styling changed over the years. Simply things like "stalactites" (pretty hanging wood carvings under the keyboard) died out in the early 1900s, so if you see that, you know it is very old. Until the 1930s, you usually didn't have legs under the keyboard. Fluting (you'll have to look that up I think) was common from 1900 to around 1925. Overdamper (where the damper is above the hammer) was more common in the late 1800s, but by 1910 pretty much everyone is making underdamper pianos. And so on and so forth... The you get to the interesting time when better materials get into it. Using an aluminium rail in the action (the action is the part with the hammers) was a significant improvement from what came before. Of course things also went the other way. Good pianos have a Sound board made of spruce. Cheap ones... use a cheaper wood, but then they laminate it with spruce to make it look good... So... yeah there was this story about a guy who went to a fight and then a hockey game broke out... well, we started with batteries, and then I went completely OT. I hope everyone had a good read
  9. Unlikely at least in theory. Though I've seen a lot of weird things in practice. If I had to guess, you were probably running a standing leakage of close to the nuisance tripping point (around 15mA), and this tiny change caused just enough of a disturbance. Or maybe you plugged in your cordless screwdriver's charger or something and forgot about it. Never discount dumb coincidence. In these cases I found that I can almost always think back to the last appliance I added, unplug it, and the nuisance tripping stops. I know only two solutions. First is to check the insulation. Probably have to get a sparky with the right equipment to do it. Second is to actually measure the residual current. Again, need the equipment. I got so fed up with this in the past I just bought the thing. My most recent excursion involved a 13mA standing loss, which I fixed by splitting the loads over two RCDs.
  10. That's the thing about an acoustic. if it is no played and tuned, the strings rust, the wood dries out, everything just goes out of wack. Whenever I see an ad saying the Piano is in perfect shape, it just needs a tune... I snigger a bit. If it hasn't been tuned, it has been neglected, and if it has been neglected, you have no way of knowing that it is in perfect shape. Presently I own a fairly plain piano. Officially it's a Carl Otto, which was the cheaper of two options (the other one was the Carol Otto), but it was rebranded as a Müller, who I believe imported these around the turn of the (previous) century. This one is estimated around 1915. It has a 3/4 steel frame (full length is better) and some pretty extensive damage to the plate was repaired somewhere in its life. But somehow it still holds a tune... at concert pitch no less. Having purchased it for 5k, I intend on playing it until it dies... which will likely be in the next 5-10 years. Hence me looking around at other options... especially with all these people emigrating...
  11. Vely vely funny.. There are over a thousand brands of Pianos and most of them are just cheap knock-offs. You want something neat, then look at a Kawai or a Yamaha. And man do they cost. I was looking at a Yamaha GB1 last week (baby grand). 165k. Car money. Can't really justify that... Oh and the naming. Bernard Steiner. Sounds Germanish? It's the higher end Pianos formerly made in Welington by Dietman. Dietman also made heaps of pianos branded under his own name, which were essentially German "Otto bach" pianos (similar components). But the one I really want is a Yamaha G2. There is one in Plet for sale right now for 80k. Still a bit much...
  12. ___

    Axpert software

    Open source merely means the source code is available. It does not necessarily mean you are not paid to write or maintain it. Paid open-source work does exist, and because of the enormous effort involved in maintaining it, lots of people are happy to pay the original guy to continue doing it. The upside of open source is that I'm not locked into a single provider. Of course I am nitpicking, you are not wrong in pointing out that the majority of open source is written because someone scratched an itch, and then released it under some very permissive license because he honestly doesn't care (except maybe to get some recognition, or to not get sued if some idiot uses his code in a medical device). What I am getting at here is the usual distinction between the two meanings of Free: Free as in beer, or Free as in freedom. Most Open source projects are both, but what really makes it good is the latter. I'm partly in agreement there. The value of a product is not what it took to make it. The value of a product is how much someone else is willing to pay for it. In that sense, this product is selling for the right price, and given the fact that no serious competition has shown up, clearly the price does not annoy anyone enough to disrupt the market and make their own (and give it away for free, as in beer). But conversely, I get annoyed when relatively simple solutions are sold, resold, and resold again, multiplying the income beyond any reasonable original input cost. Of course I think the free market principle is more important than my own annoyance, so the market can simply vote with their feet as far as I am concerned
  13. I agree with this. The Cerbo is better, yes, but if you don't want issues then run a network cable. Some Wi-Fi extenders have an ethernet plug (eg TP-Link TL-WA850RE), then you can run an ethernet cable to a clear spot and pot the Wi-Fi extender there. Also very useful, there is an Android App called WiFiAnalyzer that gives you an idea of signal strengths of the various APs, that also helps to get an idea of where to put the extender.
  14. You can connect more stuff before the thing becomes overloaded. Especially important if you plan on having multiple MPPTS (more than 3), or multiple PV-inverters, and especially when you have a three phase setup (everything times three). Then you want a Cerbo or the MP-II-GX. Also, if you want to mess with MQTT or any of those nice IoT things, get one of the faster ones. For the average single-phase residential install without too much hardware, a Venus-GX is more than sufficient though. Which is why price might be the final arbiter.
  15. Right, let's get technical... The Multiplus-II-GX (And Easysolar-II-GX) have a built-in board. This is essentially a small ARM computer. All the GX devices are. But the one in the MP-II-GX is based on a quad core 1.2Ghz Nanopi which is the fastest platform of all 4. The Cerbo is the next fastest, followed by the Venux-GX and then the CCGX. So unless the built-in GX option costs significantly more than the external one, I'd encourage you to go for it. There is one exception though: If you want to use the fancy analog/digital connections on the Venus-GX/Cerbo-GX, then obviously you have to go for the discrete solution. Also, a Venus-GX has two built-in relays. For the average guy running a residential setup, it makes little difference. Go with what makes the most sense to you.
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