Anton P Posted June 28, 2021 Share Posted June 28, 2021 Hi all, I’m new to the solar side of things and was previously using a Mecer Axpert 3Kva with 2x 200ah Oliter batteries. I had the opportunity to sell my current system and upgrade a bit. I’m on a very tight non-existent budget, but I want to do the right thing and will make a plan. I’ve upgraded to the equipment listed below and had a solar installer install my PV panels. The 3x panels are connected in series. He did tell me right from the start that I don’t have enough PV panels. He then changed the setup with the settings that he suggested, but I found that the batteries didn’t charge and felt that the batteries were used too much. (Sorry I might still be in the battery as a backup mentality). I also noticed that my batteries % according to Watchpower v1.14 (RS232 - LAN cable) showed that they were on 47% at 51.90V with a 247W load. I’m worried because the % goes below 50%... My average load during the day is about 250w - 600w max and my intention with the solar side was to hopefully be on solar during the day (saving a bit on Eskom) and then on utility during the evening. Question 1: What would the suggested settings be with the equipment I have and way of use? Question 2: Should I purchase 3 more panels and then how would they all be connected? Will it help or do I need even more? Question 3: Is it ok to use the batteries and does this not significantly reduce the lifetime of the batteries? Question 4: If a battery discharges a bit and then charges again is it then seen as a charge cycle? I have raised these questions to the solar installer and he just said that his settings are correct and should stop worrying about what I see on the display panel and software. Solar installers settings: 01: SBU, 02: 80A, 05: USE, 06: LTD , 07: TTD, 09: 50hz, 10: AUT, 11: 30A, 12: 49.0V, 13: 51.0V, 16: SLB/UCB, 18: BOF, 19: TEP, 20: LON, 22: AOF, 23: BYE, 25: FEN, 26: 57.2V, 27: 54.0V, 28: SIG, 29: 47.0V Any help or suggestions would be appreciated. New Equipment: Inverter - As per solar installers suggestion Kodak King 5Kva Off Grid 48V Model: OG-Plus 5.48 Specifications: Rated Power 5000VA/5000W Efficiency (Peak) 93% Line mode, 90% Battery mode Solar Charger type MPPT Maximum PC Array Power 4000W MPP Range @ Operating Voltage 60 VDC ~ 115 VDC Max. PV Array Open Circuit Voltage 145 VDC Max. Solar Charge Current 80A Max. AC Charge Current 60A Max. Charge Current 140A Battery 4x Oliter 200ah Gel Model: 12V200AH Specifications: Float charge 13.5V - 13.7V Average charge 14.1V - 14.4V PV Panels 3x AE Solar panels Model: AE330HM6-60 Specifications: Nominal Max. Power Pmax (Wp) 330 Maximum power voltage Vmp (V) 33.81 Maximum power current Imp (A) 9.76 Open-circuit voltage Voc (V) 41.31 Short-circuit current Isc (A) 10.37 Module efficiency (%) 19.90 Power tolerance Pmax (Wp) 0 / + 5 Maximum system voltage DC (V) 1000 Maximum series fuse rating (A) 15 Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 28, 2021 Share Posted June 28, 2021 5 hours ago, Anton P said: I also noticed that my batteries % according to Watchpower v1.14 (RS232 - LAN cable) showed that they were on 47% at 51.90V with a 247W load. I’m worried because the % goes below 50%... That's because your low battery cutoff is 47.0 V. The Axpert/Kodaks don't have a proper battery monitor, they just estimate the SOC with a crude formula that takes the cutoff voltage as -2% SOC, and adds 1% SOC for every 0.1 V that the battery voltage exceeds that setting. So (51.9 - 47.0) / 0.1 + -2% = 47%. The default cutoff voltage is 42 V, which works out better for SOC calculations (it would display 50% higher due to the 5.0 V lower cutoff voltage, so 97%!! The problem is, in South Africa you have the occasional load shed as I understand it, so running the battery down to 42 V (10.5 V per 12 V module) every load shed would ruin the battery very quickly. I would use a cutoff of 48 V (sometimes the highest possible value, though Kings will go to 54.0 V), which would make the reported SOC ever worse. Usually I would recommend using an external battery monitor like a Victron BMV, but with your stated budget ("non-existent"), you should probably print out a cheat sheet from the internet, and place it beside your inverter, so you can do your own crude SOC estimation. 5 hours ago, Anton P said: Question 1: What would the suggested settings be with the equipment I have and way of use? Even though I have a King here for experimentation, I don't know them all that well. If you keep using little PV, you probably want to use a mode where the King will blend AC-in and solar. As noted above, I would change setting 29 (low battery cut-off voltage) to 48.0 V. Setting 02 (maximum total charge current) seems very high at 80 A. Usually lead acid is limited to 0.15C, which for you is 0.15 x 200 = 30 A. I don't know your battery, it may be able to handle more than that, but I doubt it can cope with 0.4 C (80 A). 5 hours ago, Anton P said: Question 2: Should I purchase 3 more panels I don't know how you will pay for panels given your budget But yes, 1000 W is low for a 5 kW system. Remember that you have more idle power now (the inverter chews more power doing nothing). You would benefit with 1, 2 or 3 more strings of 3 panels (3, 6, or 9 more panels). Quote and then how would they all be connected? They must be very similar panels in terms of Vmp, preferably identical (but that's often hard to do). They should agree within 5%. Each string will need a separate string fuse (DC rated PV fuse of course). They should be wired 3S the same as your existing panels, unless by some amazing coincidence you can get 2S of monster panels to add up to within 5% of your existing 3S panels. All strings go to an isolating / combining / protecting box. Quote Will it help or do I need even more? As above, it will help to feed the hungry 5 kW inverter's idle draw (even if you're only using a few hundred watts now). It will also help to offset Eskom usage. If you really only use 600 W of power, then more than one extra string is possibly wasted. But now that you have the ability to use it, I think you'll find more loads to put on the inverter. Quote Question 3: Is it ok to use the batteries and does this not significantly reduce the lifetime of the batteries? Batteries are expensive. My view is that you may as well use them to save power bills. But in a high load shedding situation, it may make more sense to keep them as full as possible, so you have power for longer during the load sheds and blackouts. Quote Question 4: If a battery discharges a bit and then charges again is it then seen as a charge cycle? It's not a whole cycle. So discharging 10% and recharging back to where it was is more or less 10% of a full cycle. Quote Link to comment Share on other sites More sharing options...
Anton P Posted June 28, 2021 Author Share Posted June 28, 2021 3 hours ago, 87 Dream said: Hi Anton Can you take a pic of the label on the side of your inverter please & post. We could probably assist you faster that way. 87 Quote Link to comment Share on other sites More sharing options...
Anton P Posted June 28, 2021 Author Share Posted June 28, 2021 14 minutes ago, Coulomb said: That's because your low battery cutoff is 47.0 V. The Axpert/Kodaks don't have a proper battery monitor, they just estimate the SOC with a crude formula that takes the cutoff voltage as -2% SOC, and adds 1% SOC for every 0.1 V that the battery voltage exceeds that setting. So (51.9 - 47.0) / 0.1 + -2% = 47%. The default cutoff voltage is 42 V, which works out better for SOC calculations (it would display 50% higher due to the 5.0 V lower cutoff voltage, so 97%!! The problem is, in South Africa you have the occasional load shed as I understand it, so running the battery down to 42 V (10.5 V per 12 V module) every load shed would ruin the battery very quickly. I would use a cutoff of 48 V (sometimes the highest possible value, though Kings will go to 54.0 V), which would make the reported SOC ever worse. Usually I would recommend using an external battery monitor like a Victron BMV, but with your stated budget ("non-existent"), you should probably print out a cheat sheet from the internet, and place it beside your inverter, so you can do your own crude SOC estimation. Even though I have a King here for experimentation, I don't know them all that well. If you keep using little PV, you probably want to use a mode where the King will blend AC-in and solar. As noted above, I would change setting 29 (low battery cut-off voltage) to 48.0 V. Setting 02 (maximum total charge current) seems very high at 80 A. Usually lead acid is limited to 0.15C, which for you is 0.15 x 200 = 30 A. I don't know your battery, it may be able to handle more than that, but I doubt it can cope with 0.4 C (80 A). I don't know how you will pay for panels given your budget But yes, 1000 W is low for a 5 kW system. Remember that you have more idle power now (the inverter chews more power doing nothing). You would benefit with 1, 2 or 3 more strings of 3 panels (3, 6, or 9 more panels). They must be very similar panels in terms of Vmp, preferably identical (but that's often hard to do). They should agree within 5%. Each string will need a separate string fuse (DC rated PV fuse of course). They should be wired 3S the same as your existing panels, unless by some amazing coincidence you can get 2S of monster panels to add up to within 5% of your existing 3S panels. All strings go to an isolating / combining / protecting box. As above, it will help to feed the hungry 5 kW inverter's idle draw (even if you're only using a few hundred watts now). It will also help to offset Eskom usage. If you really only use 600 W of power, then more than one extra string is possibly wasted. But now that you have the ability to use it, I think you'll find more loads to put on the inverter. Batteries are expensive. My view is that you may as well use them to save power bills. But in a high load shedding situation, it may make more sense to keep them as full as possible, so you have power for longer during the load sheds and blackouts. It's not a whole cycle. So discharging 10% and recharging back to where it was is more or less 10% of a full cycle. Thank you for the response, so setup as is...change setting 2 to 30A and 29 to 48.0V. Any other suggestion as to setting changes? Setting 2: Max charger current = (UTILITY + SOLAR) as per manual. I think that is why the installer set to 80A - default is 60A. With the current settings will Utility charge the batteries and assist with load if solar not enough? We currently in winter so solar not very efficient and with the limited number of panels also not helping. I will be able to add an additional 3 panels at the end of the year and the combiner as suggested. Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 30, 2021 Share Posted June 30, 2021 On 2021/06/29 at 1:16 AM, Anton P said: Any other suggestion as to setting changes? See below. On 2021/06/29 at 1:16 AM, Anton P said: Setting 2: Max charger current = (UTILITY + SOLAR) as per manual. I think that is why the installer set to 80A - default is 60A. 200 Ah is pretty small (if lead acid) for a 5 kVA inverter. The worst lead acid batteries can only take 0.15C charge, which is 30 A. But perhaps yours can take more. Here is a picture I found on the web: If similar to the above, you could change it to 50 A. Though with only 1000 W of solar, solar charging will only be 20 A until you get more panels. For faster utility charging, you could increase setting 11 (Maximum utility charging current) to be the same as setting 02. Quote With the current settings will Utility charge the batteries and assist with load if solar not enough? At present, I think only if and when the battery voltage falls below that of setting 12 (back to grid). You might want to increase settings 12 and 13 (keep them at least 2 V apart) so the battery doesn't work so hard, and is more likely to be full at the end of an intermittently cloudy day. Quote We currently in winter so solar not very efficient and with the limited number of panels also not helping. In these conditions, you might want to switch setting 01 to SUB; that prioritises utility over battery for supplying the load. But I think when the sun is ample, you'd want to switch back to SBU, so the utility doesn't supply power every time a little cloud goes past. To do this switching comfortably, you'd want to have a monitoring program like Watchpower (free), so that you don't have to go out to the inverter every time you want to change this other settings. Or maybe just switch to SUB during winter, and back to SBU by spring; experiment to find what works for you. Quote Link to comment Share on other sites More sharing options...
Andries Taljaard Posted January 19 Share Posted January 19 I installed a Kodak OG-PLUS 5.48 Inverter 9x Canadian Solar Panels output 169 Volt 4x US2000 Plus Pylontech batteries Settings on inverter:- 02 - 30A 22 - AON 40 - Nrt 05 - PYL which adjust 02, 26, 27 29 automatically 23 - bYE 93 - Nrt 06 - Ltd 25 - Fd5 07 - Ltd 26 - 56 V (AUTO) 09 - 50Hz 27 - FLv (AUTO) 10 - AUE 28 - SIG 11 - 30A 29 - AUTO CONTROLLED BY 05 12 - 46V 32 - AUE 13 - 54V 33 - Eds 16 - SbL 34 - EU (54V) 18 - bON 35 - 60 MIN 19 - tEP 36 - 30d 20 - LON 39 - Ad5 The inverter do not charge the batteries from the PV panels 169V input The inverter do not use PV for house usage but drain the batteries My PC is connected via a RJ45 cable made up by computer tech 5. Code Reference: received 61 alarm which is a communication loss between batt. and inverter The above settings is more or less the same that i used on the Mecer 5kVa inverter which use Solar during the day and battery supply power during night Power consumption is 12 kWh / 24 period this include a 150 liter geyser with a 3kW element Quote Link to comment Share on other sites More sharing options...
Coulomb Posted January 19 Share Posted January 19 2 hours ago, Andries Taljaard said: Kodak OG-PLUS 5.48 Inverter So that's an Axpert King with orange paint. Unless it's an Axpert King II (these are still fairly new, I've never seen one), the absolute never-exceed PV voltage is 145 V. You're not supposed to exceed 115 V when actually operating, though in practice they'll probably work to 130 V, and start losing power from there. So 169 V is probably stressing the components in the solar charge controller. I think that there are capacitors in there rated at 150 V. I presume that your 9 panes are arranged 3S3P. They must be large panels, possibly with more than 72 cells, to have a Voc of 169/3 = 56.3 V. You'll have to arrange them as 2S4P, leaving one left over. You could use that to parallel your shadiest panel, putting the two panels most prone to shading in parallel. Or get one more panel the same as the others and make the array 2S5P, if that's not over 4800 W (i.e. 480 W panels or less). 2 hours ago, Andries Taljaard said: Code Reference: received 61 alarm which is a communication loss between batt. and inverter You mentioned a cable between the PC and inverter; is there a special (not straight through) cable between the battery's BMS and the inverter? That's what warning 61 is about, and setting 05 = PYL requires this cable. Quote Link to comment Share on other sites More sharing options...
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