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Calvin

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Everything posted by Calvin

  1. I don't know what battery you are using, and whether all batteries are the same, but for Pylontech they define a cycle as discharging the full original capacity in Ah. That means if you charge and discharge 10% a day for 8 days it will count as 0.8 cycles.
  2. I went from 3 phase land rate (fixed cost about R3.5k) to single phase prepaid (land light) when I put in my system. No fixed cost and unit cost of power still less than diesel. This works well for me because I now use very little ESKOM power - about 500 kWh per year. The conversion was slow (7 months, during lockdown) and dealing with ESKOM was annoying, but well worth it in the end.
  3. My apologies - I have obviously not expressed my concerns well. I have no doubt that the battery will pass any normal test with flying colours, and I certainly do not believe that the test will somehow be fudged. The problem is with what you can reasonably test. The characteristics that justify the high price (long calendar and high cycle life) can unfortunately not be tested easily. The high charge and discharge rates that capacitors have can also not be tested as these batteries are limited to 2C (30 mins), which is not uncommon for a LTO battery. If the test is as rigorous as the other one we will see that, just like the other one, the temperature will increase significantly when charging or discharging at full current. That will be a tell-tale - capacitors charging/discharging once an hour would show negligible heating. Detailed discharge curves will also reveal the truth: batteries have very different discharge characteristics to capacitors. That could theoretically be masked by having DC-DC voltage converters, but theses batteries clearly do not have them. Read the extensive discussion on @Coulomb and @weber 's AEVA forums (Arvio 3.5kWh drop-in-battery-replacement supercapacitor on sale - AEVA Forums) for a very detailed discussion on this topic. Executive summary: there are no capacitors available that can do even 5% of what would be needed to make these devices. I have no axe to grind here - I do not have any commercial interest in any part of the solar industry. I simply hate to see people being scammed out of their hard-earned money.
  4. We are talking about the "super capacitor" battery, which is not the one in the competition.... Also, the "super capacitor" battery is probably a very good battery. It is just not a super capacitor battery.
  5. You are welcome. I have for years been biting my tongue watching this snake oil BS being sold to unsuspecting consumers. I was very disappointed when I saw that @Powerforum Store was selling this - I can only assume that they have also been taken in by the con-artists. The beauty of this con is that the victim only finds out in 10 years that they have been scammed. A bit like the 20-year warranty house paints... The final straw for me was that @Powerforum Store is now actively promoting these. I suspect that there will be a (well deserved) glowing review, as they do not appear to have the technical knowledge to understand the con. Now at least they cannot say that they have not been warned.
  6. I am a professional engineer, and as such have been brainwashed to always be very careful when expressing opinions. People can take them out of context and you can get sued... However, I have no hesitation saying this: Having a supercapacitor battery, at this time, with these specs, is as likely as having your Golf GTI break the sound barrier. Or hitting a golf ball 1000m... 1. Do your research online - it would need orders of magnitude of improvement in the energy density of any known capacitors to achieve what these claim. 2. Even if that would happen, capacitors release their energy all the way down to 0 volts. It would be possible to have DC-DC boost converters that would lift that to 48V, but that would need large heatsinks and fans to dump waste heat. None of these "supercapacitor" batteries have them. There is a multi-billion dollar industry in electric vehicles that is investing billions into new battery technology trying to get a competitive advantage, and they would kill for technology with these capabilities. Why on earth would Sirius or Magneto (or whomever) not sell this fantastic technology to them? Go figure. So what will you learn from your long term review? That it works. Of course it does. It is almost certainly a high quality LTO battery. You would obviously not open it up, but there is a simple test. Charge and discharge it as fast as you can a few cycles in quick succession. (Supercapacitors can charge/discharge almost instantaneously). If it heats up significantly it is not a supercapacitor. (In the test referenced above one charge cycle heated the battery to 44) I will even make you an offer: Cut it open. If it has no chemical batteries in it (only capacitors) I will buy the wreckage from you at full new price. If not, sue the manufacturers for defrauding you, and stop selling it in your store.
  7. Pity some other sucker who ends up using these idiots. Apart from the outrageously poor design this installation could pose serious fire and electrocution risks. I am a great believer in "name and shame" where the evidence is so compelling. One does of course need to stick to indisputable facts when doing so.
  8. I was obviously not clear: The overshoot is a concern due to the tendency of the Voltronics inverters to overshoot the target. When your target is as high as mine (53.0V) the inverters (I have 3 in parallel) will easily overshoot to 54V (the battery cutout) if charge current is set at say 120A.
  9. I agree with you on 53.3V being too high. For me however 52.5 V is too low - it would take a too long a time to reach 100%. I originally used 52.6V on my US3000Bs but after some firmware upgrade I had to increase that to 53.0V to get it to get to 100% SOC reasonably quickly (< 5 minute gap from first to last for my 8 batteries). In order to prevent overshoot I reduce max charging current to 60A (for 8 batteries) once the voltage gets over 51.5V. Lithium batteries hate being fully charged, especially at high temperature. On a daily basis I leave them at 100% for 1 minute and then reduce the setpoint voltage to 50.5V, Once every 10 days I leave it at 100% for 10 minutes. Reducing the setpoint to 50.5V means it quickly discharges to about 99.5%, which is a small price to pay for the increase in battery life one expects.
  10. More confusion - the parallel manual you found is very different from mine! (see attached). The one you found says shared breakers, the attached one says separate. Apparently either is OK. Parallel installation.pdf
  11. Sadly, as so often with Voltronics, it rather depends on which manual you look at. The Manual I linked to above agrees with what you said. There is another manual (4KVA/5KVA Parallel Installation Guide) that clearly shows breakers for each inverter on both input and output side. Take your pick... I have mine installed as per the King manual - just one AC-in and one AC-out breaker. No problems so far (4 years) Having separate breakers on the output can cause an issue: if one trips (or is switched off) the system will detect a current sharing fault and shut down all A/C output. I quite like having only a single breaker: it removes the (very strong) temptation to "service one inverter while the other can be in service". (I am trying to give up blowing things up )
  12. I do exactly this with my 3 Kings - 2 of them have relays in parallel with the switch that my supervisory system turns off when loads and PV are low. This has worked fine now for 4 years. If memory serves me well @Coulomb has released firmware (for my Kings at least) that allows the inverter output phase to be switched off using a serial command. I have not (yet) tried using that.
  13. The bypass/ECO mode in the King is not available when connected in parallel. This is not well documented. You will find it at the bottom of page 29 of the manual on the AEVA site (USER’S MANUAL (mppsolar.com))
  14. I have ordered these and managed to flash Tasmota, but neither the relay nor the power measurement works. I suspect that the Template I used (Vizia 16A Power Monitoring Plug Configuration for Tasmota (blakadder.com)) must be wrong, which is odd as the board is dated 2018-12-07. Do you have access to a working one? If so, please could you let me have the template string that you are using? Thanks
  15. I am in the market for some additional Tasmota devices (specifically power measurement smart plugs). Has anybody recently tried to "Tasmotize" any of these new Tuya devices? Does the Takealot VIZIA Smart WiFi Power Plug Switch still work?
  16. Segen Solar have them (the original Voltronics parts) for about R100 each. You can order through any Segen reseller (I use Bonanza Technologies) Probably. I have had fans fail intermittently - They stop and start again (for a month or so) before finally giving up the ghost. If only 1 fails it gives a warning 01 (at which time it may contribute less to your system as it may throttle on account of running hot), if both fail it gives fault 01 (at which point it will stop all contribution to your system).
  17. This is exactly what @Steve87 said would happen. Leave both breakers on, switch one inverter off using the push-button switch. The push-button disables only the inverter output stage - the inverters will still operate in parallel for charging and setting synchronization.
  18. I see that @Steve87 recommended that you put individual AC breakers on the outputs of each inverter. Perhaps he meant isolating the inverter output with one of these breakers rather than turning off the inverter? Switching an inverter off (using the push button switch) does not cause any faults. It reduces that maximum load that can be supplied, and saves about 60W in power.
  19. Hi @Coulomb, Like you and Weber, I have spent many hours trying to understand the settings and terminology of these inverters (also with limited success ). I would be very happy if I am wrong, but I have never found any difference between ECO and Bypass modes on the King. Irrespective of the terminology, my 3 Kings (parallel single phase) always power the loads from the inverter stage. The settings that make it bypass as a standalone simply have no effect when paralleled. So, if you have any ideas about how this could be achieved I would be very happy to test it on my setup.
  20. Bypass(ECO) mode is not available on paralleled Kings. This is mentioned in a version of the manual available on the AEVA site. (USER’S MANUAL (mppsolar.com see bottom of page 29)
  21. Not strictly correct. "In 1842, Julius Robert Mayer discovered the Law of Conservation of Energy. In its most compact form, it is now called the First Law of Thermodynamics: Energy is neither created nor destroyed" Einstein spoiled the party a bit when he came up with the famous E = mc² (his theory of special relativity), which brought mass into the picture.
  22. No I did not - I was not aware that it can be done and anyway I have nothing to hide - my batteries have had a very uneventful life. Anyway, as @PierreJ said I would have thought that that would be a sure-fire way to get Pylontech to refuse a warranty claim....
  23. I have 8 US3000Bs that I have upgraded twice, and all the historical data have survived the firmware upgrades.
  24. Mecer and Kodak and RCT (and some others) are simply rebranded Voltronic Axperts. For instance, a Kodak OG plus 5.48 is an Axpert King 5kW. Get whatever one is the best price, but avoid the clones.
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