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Calvin

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Calvin last won the day on August 11

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  1. The 80A is essentially the maximum recommended value. If your batteries will charge fully at a lower setting, by all means use it. Generally, lower current is better as the power wasted (because of the internal resistance of the battery) goes up with the square of the current. This wasted power also heats the batteries, which is not a good thing.
  2. I have done this, and it is indeed not trivial if you want to do it well. The biggest challenge turned out to be finding how much excess PV is in fact available. When the battery is charging at the maximum allowed current (or is full) the SCC will clip it's output to what the system can use. First I tried looking at the MPPT voltages - the logic being that if they are higher than the maximum power point, the SCC has pushed them up to reduce power, so there must be spare PV out there. This worked OK but not fantastically - perhaps complicated by the fact that I have 3 inverters in p
  3. The inverter setting is total charging current, not per battery. So, you should set 80A - it will be divided by the BMS between the batteries.
  4. I am also a farmer with similar usage as you. I have gone off-grid for the sort of cost you are talking about (R350k because it was DIY), but be aware that you may need to buy at the lower end (Axpert) rather than the Victron at your budget. Real key is whether you intend keeping the ESKOM connection (with it's massive fixed connection charge), switch to a Land Light 60A single phase (no connection charge but over R5/kWh) or drop ESKOM entirely. For me the sensible option ended up the 60A single phase - it is essentially a hassle free generator at lower costs than running a generato
  5. It is quite simple in principle, but as is often said the devil is in the detail. Essentially the microcontroller measures the available incoming PV, the outgoing AC (to loads) and DC (to the battery) and estimates the system losses in order to calculate what spare power is available. It then adjusts the power to the geysers every second to use exactly this excess power. The only problem with it is that it is complicated (it does many other things) and home-grown - I used to do this sort of thing professionally and now that I am retired it is my hobby. Unless you are a competent pr
  6. Quite right. I have a microprocessor that controls my energy system and it also controls both my 3kW geysers with triacs, meaning that I can send any excess energy to the geysers. The beauty of using analogue control is that you don't have to wait for 3kW to be available - you can balance the system perfectly. A further advantage is that you now really don't need extra inverter capacity for your geysers - the system monitors for overload conditions and switches off/reduces the geyser power instantly if too much other loads come on line.
  7. Axpert, Mecer, Kodak RCT and many more are brand names. All these inverters are in fact simply re-branded Volronics inverters. VMIII, Kings MKS are models, sold under all the different labels. So, a Kodak King is the same as a Mecer King, but a Mecer VMIII is very different from both. So, the key is the King or VMII part, not the Kodak or Mecer or whatever. Hope this clarifies it. Ignore everything I said earlier - my knowledge / advice is limited to the Kings.
  8. NOOOOOO! It REALLY can only be one or the other.
  9. Does the display show battery charging happening? (Use Watchpower if you do not know where to find it) What is the battery voltage? Is it in PYL mode (setting 5)? If yes, try setting 5 USE setting 12 47V setting 13 51V setting 26 52.5V setting 27 50.5V setting 29 45V
  10. This makes no sense. The utility supply is disconnected, and yet the inverter is drawing 480W from it? There are several people here with the knowledge and inclination to help, but we are flying blind. May I suggest that, in order to get assistance, you provide the following information: Inverter model Firmware versions Settings actual values of power from the LCD Of course the inverter could be faulty, but the chances are far greater that there is a problem with the settings or setup. For reference, the King uses about 80W when fully powered up with no
  11. Something I wrote when planning my own installation. I will upload it as soon as I have had a chance to polish it a bit...
  12. This should work: 1. Charge each battery individually to 100%. You will probably need to disconnect the others. 2. Reconnect, making sure that the 3.5 is master (Link port 0 unused)
  13. 12/4/4 below Just to put it clearly: below is the numbers for North vs West vs East on 1 July in Pretoria (26 degrees panel angle) As you can see the West and East facing panels are not bringing much to the party. Slight gains early / late, huge losses rest of the time.
  14. No problem - adjusted to 26S 28E All 16 North 4 West, 12 to North 4 to West, 4 to East, 8 to North You need to be careful here: moving panels like this gives you more early and late, but in July total daily production decreases from 5.4kWh to 4.4kWh (per kW installed). Given that most of us size our systems for winter, losing 20% in winter is not ideal... Also note that these figures are for the case where each bank has it's own MPPT to optimise it's production. If you combine different orientations on the same MPPT you will lose a lot more.
  15. Looking at your graphs it appears that you are already wired 2S. Given that a hardware issue is unlikely (2 different inverters), the strongest remaining possibility is in your settings. (I have had similar behaviour on my King when I had screwed up a setting) Please list all your settings, and the inverter firmware version.
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