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Thank you for the great forum, Safe Driving over the weekend. Sincerely Jason


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Coulomb last won the day on February 3

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About Coulomb

  • Birthday 05/11/1958

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    Brisbane, Australia
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    Solar energy systems with storage; firmware for inverters and chargers

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  1. Are you saying that ICC can talk directly to the BMS, even in systems without a battery type of PyL? But this communication is used only for SOC display? That would seem to mean that you'd never need a Victron BMV if you're using a system with ICC and a PylonTech battery. Is PylonTech the only battery so supported? Do other battery brands emulate the PylonTech protocol sufficiently to achieve the same end?
  2. Using 40.5 for the low DC cutoff voltage setting (setting 29 on Axpert inverters) probably won't harm the battery too much (though it encourages deep discharges, which are not good for battery life). It could damage the inverter, as it may go crazy when the battery disconnects while the inverter is powering a load. Using a bulk/absorb voltage setting (setting 26) of 54 V will again prompt the BMS to protect the cells, with possible damage to the inverter. In an ideal world, the inverter and BMS would co-operate to charge the battery. This is what happens with battery type PyL and the appropriate cable and firmware, with inverters (Kings and VM IIIs) that have the PyL option. Absent that, BMS intervention is really an emergency brake; good to have it for safety, but not to be used daily.
  3. It's certainly possible to update the firmware on KS (PWM) models. It's just that they're less common, so there are fewer firmware updates for those models. The voltage sensing is usually pretty reasonable, though at times they could do with adjustment, and there are special commands for that purpose. The problem is that voltage, even measured perfectly accurately, is a very poor estimate of state of charge, for the LFP chemistry in particular. No settings adjustments will compensate for the fact that Axperts don't have a battery current sensor, and so can't accurately estimate battery SOC. 45 V is awfully close to 44.5 V, where Pylontechs are said to disconnect via their BMS (see this post). If one or more cells is weaker than the others, that voltage could increase.
  4. I'd have a go at answering this, but I need a link to whatever information you have so far. I wasted about 10 minutes trying to find it; your post seems riddled with spelling errors. You say your daily usage is "approx 5kw". Do you mean your power usage regularly peaks at 5 kW, or that your daily energy draw from utility is about 5 kWh?
  5. There are limits to what ICC can do to control the inverters. It can't change the SOC guesstimate, for example. If you don't have a recent Axpert King or Axpert VM III with the special cable to the PylonTech BMS, and battery type (setting 05) set to PyL, then if you want accurate SOC measuring, you'll need a Victron BMV. It will have a good SOC estimate. I'm not sure if ICC can read this estimate (I think it can), or if you have to read it from the BMV display. You then ignore the SOC reported by the inverter's LC Display.
  6. Arrgh! My bad. I made a typo in my response to your setting 27, float battery voltage. It should be 54.2 V, not 52.2 V. So change setting 27 to 54.2 V, and the battery voltage reading at the same stage should be close to 54.2 V. Then everything should be in order. Sorry for the stuff up.
  7. That RJ-45 connector is an RS-232 port. You can't connect that directly to USB. The inverter should have come with an RJ-45 to serial cable. It's non-standard; pinout here. You would then use an off-the-shelf USB to RS-232 adapter to connect to a computer's USB port. Something like this:
  8. That's an average of 13.1 V per 12 V module. That's quite high if the battery isn't being charged, and astounding if it's supplying a load. If it's supposed to be float charging, it's quite low. If it's supposed to be bulk charging, it's OK only if it's just started bulk charging. In short: one reading without knowing more about the system state doesn't tell much.
  9. You probably don't have the special cable for connecting the BMS of the PylonTech to the RS-485 port of your King. It has to be a recent model (made in the last 12 months or so, preferably later than that). Then you need to change the Battery Type setting (setting 05) to PyL. Without the above, the SOC reading is for entertainment value only.
  10. Perhaps you have power saving turned on? Setting 04. I prefer SDS (disable). Otherwise, add a load of at least 100 W and see if it stops pulsing (assuming that it is pulsing on and off).
  11. Err, sorry. Schubarts are clones, not exactly the same as a Mecer at all. The ¢ symbol on the label instead of the Φ symbol (for "phase") is one of the giveaways. So who knows what is in there, and what quality of parts they used. Let's presume for now that they copied it properly, and it works the same as a real Voltronic Power inverter. With a Voc of 45.93 V at 25°C, that's over 138 V, well past the 130 V derating point (again, assuming they copied that behaviour from the Axperts). You really should have wired them 2S; it sounds like that's how they were wired originally. It might be worth trying a single pair of panels, to see if it charges properly from a pair of panels wired 2S. If so, then wiring them all 2S is an option. Unfortunately, that means only 8 panels on 2 inverters, 10 on one, and one unused. When winter comes around, on a frosty morning those panels will generate perhaps 147 V, which could damage the solar charge controller. In reality, it will probably survive. It might be possible to re-flash the firmware to 73.00e even though it's a clone; this would at least overcome the premature float bug. But it might brick or damage the inverter. Sorry; there are no easy answers for this situation.
  12. You're quite correct; my bad. Here is my block diagram to cover most of the Axpert models: Ignore the red part (for Axpert King only) and the blue lettering and line (for 145 V max MPPT only). But since the max PV is say 4 kW and the inverter can handle 5 kW, the inverter isn't in a place where it will be the bottleneck. Let's say there is a 6 kW load, and 2 kW of PV. The inverter is rated at 5 kW, so it is forced into line mode, so the top switch is closed. So power can flow from the AC-in to the AC-out. But in SUB mode, the other switch would also be on, so that PV power can flow to the load as well. The inverter can't handle all the load, but it doesn't have to; the AC-in is there to supply part of the load. So 4 kW will come from AC-in, blending with 2 kW from the PV, to provide 6 kW to the load. The inverter only carries the PV-supplied portion of the load. It's possible for part of the PV power to charge the battery, via the bidirectional DC-DC converter (at right). In that case, less power supports the load, obviously.
  13. So it sounds like you have an off-grid inverter, not a hybrid. It sounds like it's an older inverter (or more than one in parallel), with a 145 V max MPPT voltage. These solar charge controllers start power limiting at 130 V, and produce zero power at 145 V. It also sounds like you recently upgraded your panels from a 2S configuration, to new panels in a 3S configuration; is that correct? A little more information in your posts would be helpful. So it sounds like you have three inverters; 68 A x 120 V = 8160 W, and you say you have 9 330 W panels per inverter (so nominally just under 3 kW per inverter). If Vmp is 120 V, then Voc will be a lot more, possibly exceeding 130 V where power will limit. Perhaps it is limiting power so much that the panels can't get started, lowering the panel voltage below the 130 V derating point. Can you post some information about the panel voltage, and preferably also the panel power? The other thing is that you could be suffering from the premature float bug. One solution would be to run patched firmware version 73.00e.
  14. I would just point out that the Axpert II in the kettle example was in line mode, so the inverter proper (the DC-AC power converter) was not in use. [ Edit: except for PV charging, see next several posts. ] So the name plate rating of the inverter doesn't come into play; apparent power output is then limited by the rating of the transfer relay. In the case of the 5 kW models (and quite possibly the 3 kW models as well, I don't know), that's 40 A, so the AC-out could handle over 9 kVA of apparent power (and over 9 kW of real power if it's a purely resistive load). Granted, you can't power any "non-essential" loads that aren't connected to AC-out. However, I strongly suspect that the Axpert MKS II and other models with this blending feature will try to not export power (from the inverter's point of view) under any circumstances. So you'd never be able to power those non-essential loads (any not connected to the inverter's AC-out terminals) from PV with this sort of inverter.
  15. What firmware version did you have before, and what are they now?
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