Colin Posted May 24, 2022 Posted May 24, 2022 My setup is 2 Axpert 5000/5000 inverters in parallel each with their own solar bank, one with 3.8KW the other 3.2KW. Connected to 14.4KWh Pylontech batteries. Running ICC to monitor. I'm Off-grid with generator for backup It has recently seemed to charge way less than before, I used to frequently have max PV for the Day over the 7KW shown on the ICC, now it seldom goes much over 4.5KW. Occasionally during the day it will spike to 6-6.5KW, but only for a few seconds. I have tested the panels individual current and all are similar current on any given day indicating that they are all charging. ICC also indicates different way PV watts to the V*A calculation, attached screen shot at 13h30 today with full sunshine, where it used to charge well over 6KW. Also attached screenshot showing PV Watts for the day, you can see average around 4.2KW, also for some reason reducing around mid day. Anyone any ideas where to look? Perhaps solar panels failing especially when hot mid at day? I did try contacting ICC for some assistance and explanations, but they were not very helpful at all Quote
ebrsa Posted May 27, 2022 Posted May 27, 2022 If you post the battery graphs one would be able to see what is happening while batteries are being charged. I have 2x4Kw Axperts with a 240AH diy battery and controlled by ICC on an RPi3. Works perfectly although solar power is down since it is winter with frequent cloudy days. Colin 1 Quote
Colin Posted May 27, 2022 Author Posted May 27, 2022 17 minutes ago, ebrsa said: If you post the battery graphs one would be able to see what is happening while batteries are being charged. I have 2x4Kw Axperts with a 240AH diy battery and controlled by ICC on an RPi3. Works perfectly although solar power is down since it is winter with frequent cloudy days. Thanks for the reply, I will post screenshot later today after its been charging for some time. Have had the system running for 3 years now, so not sure its ICC thats the issue, but trying to understand the readings from ICC to get to the problem. Basically. I seldom get over 4KW on 7KW of panels even on cloudless days. Don't recall that happening last winter. Need to find out why. Faulty MPPT, panels, wiring, inverter? Quote
GTP Posted May 27, 2022 Posted May 27, 2022 Could it be gammy cells in one of your batteries throttling charge power? Quote
Colin Posted May 27, 2022 Author Posted May 27, 2022 38 minutes ago, GTP said: Could it be gammy cells in one of your batteries throttling charge power? How would I check? ICC shows all 7 batteries much the same valtage and current, I would assume this means all OK? Only glitch on the reading seems to be the No. of cycles sometimes goes to zero on some batteries, changes randomly for some reason. Below screen shot ICC batteries Quote
GTP Posted May 27, 2022 Posted May 27, 2022 I am not sure. I mentioned it because I experienced an issue where my charging curves became erratic. Mainly the charging was being throttled. I also noticed that the battery would not discharge to the SOC that was configured. The bms showed no problem and SOH of 100. My installer together with his supplier then determined it was a rogue cell that was charging faster than the others and would cause the throttling when this cell apprpached full charge, whilst the other cells tried to catch up leaving a battery that took longer to charge. I wouldnt know how to check this though. Apologies. I simply reported the symptoms to the guys in the know Quote
Colin Posted May 27, 2022 Author Posted May 27, 2022 Below pics of PV vs Load vs battery Not the ideal day for reference as some cloud cover. Also for info 1KW geyser load came on around 12h30 Quote
ebrsa Posted May 27, 2022 Posted May 27, 2022 @Colin at about 12h30 your battery voltage rises exponentially which is normal behavior for LFP cells when almost at 100% charge. My charge amps fall sharply as the float voltage of ICC and therefore the Axperts is set to 53.7V (16 cells). My Axperts are flashed with the latest firmware by @Coulomb (also known as Aussie firmware) and it allows me to see the charge current of of each inverter. I can't remember what the factory firmware displays. Perhaps you should investigate if there is an Aussie LFP firmware for your inverters if you have the courage to flash them. I have flashed mine many times as newer versions became available and also for others without mishaps. However it remains a personal decision and if it goes wrong you have an expensive paper weight or two on your hands. It seems that LFP batteries should not be kept at a float voltage but apparently little happens at a cell coltage below 3.4V and mine at 3.36V was recommended by @Coulomb. There are also detailed articles on https://nordkyndesign.com/. Perhaps you should switch the load to grid and then check what the charge amps or watts are on each inverter to narrow down the source of the low PV watts. Quote
Colin Posted May 28, 2022 Author Posted May 28, 2022 (edited) Today I physically measured volt and amps form the solar panels with DC clamp meter: Measured - Inverter A: 37Amps 85V = 3145W Inverter B: 39Amps 67V = 2613W Total 5758W ICC shows MPPV - Inverter A: 46Amps 84V = 3864W Inverter B: 58Amps 67V = 3886W Total 7750W ICC also shows solar PV 4800W?? Also, my connected load currently 900W and charge measured to batteries is 3500W thus total 4500W, where is the rest going, surely not inverter and losses so much? Connected panels - Inverter A 3800W Inverter B 3200W Am I correct that ICC is reporting incorrectly?? If so, Would this be fault from ICC or the inverters Edited May 28, 2022 by Colin Quote
Coulomb Posted May 28, 2022 Posted May 28, 2022 Part of the confusion will be that Axperts report PV current on the battery side, not the PV side. PV watts are reported correctly. So that explains why panel voltage time reported PV current (85 x 46 = 3910) exceeds nominal panel power (3800 W). There is also the confusion as to whether the currents are total (charge current plus load supporting current, battery-side) or charge current only. You have 3.8 + 3.2 = 7 kW nominal PV; on a good nearly winter day you might get 75% of that, or 0.75 x 7 = 5.25 kW, so ICC reporting 4.8 kW seems reasonable. You'll need a larger load to find out if the currents reported are charging only or total. Colin 1 Quote
Colin Posted May 28, 2022 Author Posted May 28, 2022 3 hours ago, Coulomb said: Part of the confusion will be that Axperts report PV current on the battery side, not the PV side. PV watts are reported correctly. So that explains why panel voltage time reported PV current (85 x 46 = 3910) exceeds nominal panel power (3800 W). There is also the confusion as to whether the currents are total (charge current plus load supporting current, battery-side) or charge current only. You have 3.8 + 3.2 = 7 kW nominal PV; on a good nearly winter day you might get 75% of that, or 0.75 x 7 = 5.25 kW, so ICC reporting 4.8 kW seems reasonable. You'll need a larger load to find out if the currents reported are charging only or total. Thank you, makes sense. Only issue I still do not understand why is that the system definitely appears less efficient over the past few months. This is just from observations, batteries used to be full around 9h30am summer and 11am winter, now only well after 12. I never went in depth until I started noticing change. I'm stumped as to what the issue is, or even if there is one, as all seems to work properly, and as you say system appears to be producing as it's supposed. Quote
Colin Posted May 31, 2022 Author Posted May 31, 2022 FYI, those thinking of buying ICC: I just posed the same questions above to ICC and received a very rude reply from a Riaan Heath of ICC, Diversified Solutions. He basically blamed me for not understanding the ICC, instead of tying to educate me on it. His final words in the email quote "I WILL NOT RESPOND AGAIN, as there is NO USE." Hows that for customer service! NOT I received 10 times better assistance from this forum, thanks guys. Afraid he has lost a customer and any future recommendations for his product Quote
Colin Posted June 1, 2022 Author Posted June 1, 2022 Can anyone tell me why I have these spikes in the solar wattage too? This is on a cloudless day, so unlikely to be from cooling, and it seems to happen every day, with or without clouds Quote
John Posted June 1, 2022 Posted June 1, 2022 On 2022/05/31 at 9:33 AM, Colin said: FYI, those thinking of buying ICC: I just posed the same questions above to ICC and received a very rude reply from a Riaan Heath of ICC, Diversified Solutions. He basically blamed me for not understanding the ICC, instead of tying to educate me on it. His final words in the email quote "I WILL NOT RESPOND AGAIN, as there is NO USE." Hows that for customer service! NOT I received 10 times better assistance from this forum, thanks guys. Afraid he has lost a customer and any future recommendations for his product Hi are you getting assistance from [email protected] Normally Mannie responds promptly if not with very detailed answers but I have never gotten a response like the one above. I know there is some confusion with 2 different companies offering the software but you seem to have an updated version. Quote
ebrsa Posted June 1, 2022 Posted June 1, 2022 @Colin I don't know who Diversified Software is but the developer of ICC is Manie and as @John suggested above send an enquiry to him at [email protected] or post one on the website. Manie is sure to give you the right explanation. Quote
Colin Posted June 2, 2022 Author Posted June 2, 2022 My original email was addressed to [email protected], the reply I received was from Riaan Heath at [email protected] and copied in was [email protected]. All subsequent replies were the same, never had any reply from Manie, but [email protected] was copied in all emails Quote
ebrsa Posted June 4, 2022 Posted June 4, 2022 That is disappointing. Perhaps try lodging a question on the website. Quote
Colin Posted June 5, 2022 Author Posted June 5, 2022 Unfortunately web site takes back to [email protected] Another issue, not sure if related, but the batteries jump from 90% state of charge up to 99% every time, then seems to loose that same 10% fairly quickly. Its like I have 10% less battery capacity. See graph below. At 12h25 full then a jump to99%. Used some fairly large loads down to 85%, then 15h00 another jump to 99% Quote
ebrsa Posted June 5, 2022 Posted June 5, 2022 (edited) ICC displays what tne battery BMS tells it the state of charge, volts and amps sensed are. The state of charge will drop suddenly when full charge voltage is reached as the charge amps drop to near zero but the load is still there. I have a DIY battery with BMS but information to ICC comes from a Victron Smart Shunt. Even so my ICC displays similar graphs. For a good understanding read Protection and Management of Marine Lithium Battery Banks on Nordkyndesign.com. All articles on lithium batteries on the website are worth reading for better understanding of LiFePO4 batteries. Edited June 5, 2022 by ebrsa Colin 1 Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.