Bront

I use SolarAssistant and the figures are very inaccurate, somewhere in the 20% range.

My batteries have different firmware, so could that be it?

I swapped the master battery setting to USE. They immediately started charging harder and on average went from 20A per battery to 30A. The inverters also swapped who was the master. Apart from these two things nothing else has changed. So hasn't really fixed anything.

PV stayed near zero for 30 seconds until I removed the load and then it ramped up to recharge the batteries. About 20 minutes later I did the second test with less load. Here are the temp graphs for the first test. My inverters have very good ventilation, and both fans sound similar. I'll try the USE setting and report back.

The maximum charging current, #2 in the manual, is set to 10A, default is 60A. However, if #5, Battery type is set to Pylontech (PYL), then programs #2, 26, 27 and 29 are set up automatically. My master inverter is set to PYL and my slave to User-Defined, (USE.) USE automatically sets programs #26, 27 and 29. I've tried changing #2 on both but they go back to 10A. So, unless I change my master to USE, I don't think I can change the maximum charging current #2. Both inverters have the battery voltage within 0.1v, so that seems ok. Any idea as to why the solar shuts down when under large loads? The load was only 3000w more than the solar was producing and the batteries were handling that just fine, so I don't get it.

I've been doing some testing and have identified the following problems. Although the 2 systems are identical, one makes considerably more solar than the other. A max of about 3000w from 1 and 2000w from the other. This makes no sense to me, unless the info I'm getting is incorrect. My Solar Assistant agrees with the inverters panel info. However, sometimes the info doesn't add up e.g. Load 8657w, Solar 5092w and Battery -2666w. There is 899w missing. If that 899w was solar for inverter 1 it would make a lot more sense. I carried out a large load test around midday on a full sun day. I had a load around 8000w with 5000w coming from solar. After 2.5 minutes the solar dropped to 90w. At the same time the bus voltage dropped a lot. I've no idea if these are related. From previous experience the inverters would have shut down shortly after, if I didn't reduce the load. I then carried out the same test with 6500w for just over 10 minutes and it was fine. Bus voltage was more stable. Why are the 2 solar amounts so different? Why is the solar shutting down with a big load? Why is the info incorrect? How many wt should I get out of 7260w panels facing north, angled at 35 degrees, situated at 34 degrees south, in full sun, at midday?

I finally have my setup complete. Just to refresh I have the following. 2 Kodak OG Plus 5.48 inverters (Axpert King 1), 2 Pylontech UP5000 batteries and 12 Canadian Solar CS7L-MS-605 panels in 3S, 2 per inverter, Solar Assistant with Orange Pi, cabled to each inverter and 1 battery. All firmware up to date, except batteries have different versions. Going 3S has fixed the problem of the one inverter idling around 100w. However, I still have a problem with the solar output from one inverter being considerably lower than the other. They get exactly the same amount of sun. I've tried swopping the panels around and which inverter is the master. The problem stays with the same inverter. I'm also getting confliction information. Each inverter's display shows double the amount of PV amps they are actually producing. Solar assistant shows the correct amount. PV watts also appears to be about right, maybe? I also feel that I'm not getting full power out of the panels. I've 7260w worth but the most I've seen is just under 5000. How accurate is the info on the inverter screens normally? How accurate is Solar Assistant? Is there a way to check the values or calibrate them?

slave U4 Slave.pdf

Here's U4, both the same firmware but no idea if it's the latest. This morning the Master solar charging ramped up immediately and the slave followed shortly after but still producing considerably less. Hopefully one problem fixed by 3S. Will next try swopping which inverter is the master to see if the problem stays with the specific inverter or moves. U4 Master.pdf U4 Slave.pdf

Ah ok, maybe he sent me those while he was reconfiguring the panels.

I also see that my batteries have different firmware. One is B69.13.1.0 and the other B68.2.0.0 Would this have any effect on anything? Could it explain why my Solar Assistant doesn't add battery values correctly?

On the configuration page of the Solar Assistant, some of the parameters with an arrow next to them, aren't changeable when you click edit. How do you change those?

Here's a bit of an update. Today we reconfigured the panels to one 3S per inverter. The master stuck at a bit over 100w for a few minutes while the slave immediately ramped up. About 10 minutes later the master ramped up to the usual 50% to 80%, or so, above the slave. So that didn't fix that part of the problem. I want to see what happens over the next couple of days to see if the idling around 100w stops. The PV voltage sits around 115v with little to no load and around 90 to 100v with load. 115 is right on the limit so guess time will tell if I have the same problem as Sam79. We also changed the cabling to the Solar Assistant. We now have a cable to each inverter and 1 cable to the master battery, hopefully we'll get better info. However, I do see that it doesn't add values up correctly in some cases. I've written to them asking about that. We tried to check the firmware version. We only get values on U1 and U2, U4 showed all zeros. Both master and slave had the same numbers. Does U2 look like the SCC firmware? master U1.pdf Master U2.pdf

The MPP range @ operating voltage is 60-115 vdc with a max open circuit of 145vdc. As I'm getting 80v 2S I'm probably going to have 120v with 3S. Will that be too much? What is bus voltage? Mine from today.

Yes, you're right, the King 5KVA has exactly the same specs as the Kodak OG Plus 5.48. I've edited my post above. At the moment I have 8 panels, but I have another 4 on order. Then I was going to do 4 of 3S. They are only due to arrive mid next month though, so probably up and running by end of the next month. We were going to try connecting all 8 panels to the master inverter, but it would still be 4 of 2S, so same voltage. I'll see if I can get someone to try a 3S set up but think it would be worth doing it on both inverters. That will possibly tell me if the slave has a problem or not. I'll also try to get them to check the SCC (U4) firmware. The slaves' panels were at almost 80v while it was idling around 100w today and the most I've ever seen the batteries at is 52.3v. Normally they are 49 to 51v but I guess that may not be 100% accurate. I've tried disconnecting the slaves' panels, when the masters were sitting around 100w, to see if that would make them charge properly but it made no difference. Thanks Coulomb, I really appreciate your knowledge. For some reason it won't let me buy you a coffee though!