September 17, 20232 yr Hi Coulomb, is this an issue you guys are trying to resolve with patched firmware, It's something that we'd like to resolve with patched firmware, but first we have to understand the nature of the problem. We looked at it for a few days (one day per week), and make no headway, and this firmware has been so long in the making that we decided to release it without the PV fix. If and when we can pinpoint the problem, a fix should be relatively easy. I'm behind several posts on this; maybe you guys have figured it out already.
September 17, 20232 yr I have noticed that the setting to limit PV input to max charge current seems to be set by default. I've often wondered about this setting. At one point, I was convinced that it was the culprit, since it seems to fit the data, as you have found. The EEPROM default is to have balance on, i.e. to NOT limit solar output current to the maximum charge current setting. But as far as I can tell, it's not used by any of the logic that sets charging currents. Although I thought I believed that at one point; things are a bit hazy now that I've been out of that space for half a month. To put your mind at rest, and mine too, you should be able to send a PSPB1 command (with appropriate CRCs and carriage return of course) to the inverter. The display should "let it though" to the DSP, and thereafter QPIRI should report a different value, and Solar Assistant should show the other behaviour. What concerns me is that without the processing of the solar balance setting, the code must be "baked in" to use one or other behaviour. Maybe it's using the wrong behaviour. Unfortunately the code to handle all this is exceedingly complex. We're going to have to use lots of crude "cave man debugging" to sort this one out. But first we need (a) time, and (b) we need a known set of conditions that demonstrates the problem reliably. Perhaps also (c) inclination, but you guys can help with that by reminding us 🙂.
September 17, 20232 yr During charging of the battery under 89% I get a peak solar input of roughly 6000-7000watts which I think is ok for an 8000W array? Yes, that's good. I wonder if you're going to float mode when the problem happens? I assume that this is with factory firmware, which all have the premature float bug. When you get to float stage, depending on settings, you can get a relaxing of the battery voltage, which means that the charge current to maintain the lower voltage is lower. Though the higher load to keep the battery under 90% SOC would reduce the current available to charge the battery, so I would expect the premature float bug to still bite, perhaps even harder, with the higher load. But then again, it might keep the battery voltage just under the bulk/absorb threshold less a small voltage, so that the "go to float" criteria are not all met. Can you check the charge stage from your logs, or perhaps just watch the charge LED to see if it stops flashing when you get the plateau in solar charge current? Or try the patched firmware, and see if this plateau goes away?
September 19, 20232 yr @Sam79 are you using BMS communigation between the inverter and battery? @Coulomb I am away for this month but I will ask somebody to check. I will try to update the firmware when I am back!
September 19, 20232 yr @John, yes I've got a kadok 3.6kw battery. Which is setup with coms to the inverter and solar assistant directly. I have noticed the battery charge amps are total different if I compare the inverter battery charge reading (20amp) to battery input reading (50amps). Which only goes to confirming my inverter is miss reading pv input and that is having a knock on effect. If I don't have a load and the sun is going for it, my battery bms reads 2900w - 3100w input vs 1800w - 2100w pv input from the inverter.... All abit messed up. Truth be told I which I had just spent the extra cash and gone sunsynk...
September 20, 20232 yr If I don't have a load and the sun is going for it, my battery BMS reads 2900w - 3100w input vs 1800w - 2100w pv input from the inverter.... All a bit messed up. Ah, OK. That can't be confusing panel versus battery current, or net battery current versus total solar generated current. Unless the grid is supplying the difference. Have you checked either panel power (panel voltage time panel current) or battery charging power (battery current times battery voltage) against the reading from a clamp meter and multimeter?
September 20, 20232 yr @Coulomb I have it set to only charge from the solar. Voltage from pv I've checked but amps I don't have access to a dc Amp meter at will read this level of amps. Hopefully the sun comes out today and I can screen shot what solar assistant is showing. Inverter reading are different to battery bms reading is my thoughts... Penny for yours... Edited February 19, 20242 yr by Sam79
September 20, 20232 yr So battery is receiving 1771watts according to bms. Load seems correct as it's a my geyser with a 1.5kw element in it. So pv input should read 3363watts 3363watts seems correct as it's 6x600w panels with good orientation and tilt. I also have had to change inverter battery setting to "user" otherwise the inverter sends to many amps to the battery and the battery tells the inverter to take a walk...
December 6, 20232 yr On 2023/09/20 at 1:32 PM, Sam79 said: So pv input should read 3363watts Which inverter you running that is also reporting the lower than expected Solar PV Watts?
December 6, 20232 yr It's the Kodak og plus 5.48. The one with the low volt mppt.. Edited December 7, 20232 yr by Sam79
December 7, 20232 yr 13 hours ago, Sam79 said: the Kodak og plus 5.48. The one with the low watt mppt.. I think you mean the low voltage MPPT, i.e. 145 V max PV.
December 8, 20232 yr On 2023/12/06 at 2:23 PM, Sam79 said: It's the Kodak og plus 5.48. The one with the low volt mppt.. On 2023/12/07 at 3:47 AM, Coulomb said: I think you mean the low voltage MPPT, i.e. 145 V max PV. A so Axpert equivalent
December 8, 20232 yr 1 hour ago, grant.cpt said: A so Axpert equivalent They're actual Axperts, made in the Voltronic factory, with Kodak branding. All Axperts are rebranded. But the model names are up to the company ordering the inverters. A colleague and I maintain a post with several of the mappings, for Mecer, Kodak, MPPSolar, and more.
February 12, 20242 yr On 2023/09/20 at 1:24 PM, Sam79 said: Which cable are you using to read the data from the Battery BMS? Also, what battery are you using?
February 12, 20242 yr I got the cable from solar assistant and plugged it into the consol port on the pylontec master. I have since changed batteries to the kodac 5kw ones and my solar issue has resolved itself
February 12, 20242 yr 1 hour ago, grant.cpt said: Which cable are you using to read the data from the Battery BMS? Also, what battery are you using? I was using the solar assistant cable. To a bl3.6 Kodak battery..... Which by all accounts is a polyontec battery set up wise..
March 17, 20242 yr I changed my Axpert king 5kv to a Fivestar 15kv hv unit. Picked it up at a good price and was offered a good price on my King. With the existing 8x480w panels now rearranged into 8s from the 2s4p setup. today its a rainy, overcast day and at 11am it was generating 800w-1.1kw to charge the batteries. Where as on a sunny, clear day on the king it averaged 1.3-1.4kw. max i have seen generated was 1.7kw. Busy with a 2nd 9 panel pv string at moment to add on to the system. So not sure if the King was a issue with pv generation or the newer higher voltage setup is just that better and more efficient. The new setup has been running for 2 days so far and i will monitor over the coming week.
March 17, 20242 yr 7 hours ago, razzor13bt said: I changed my Axpert king 5kv to a Fivestar 15kv hv unit. Picked it up at a good price and was offered a good price on my King. With the existing 8x480w panels now rearranged into 8s from the 2s4p setup. today its a rainy, overcast day and at 11am it was generating 800w-1.1kw to charge the batteries. Where as on a sunny, clear day on the king it averaged 1.3-1.4kw. max i have seen generated was 1.7kw. Busy with a 2nd 9 panel pv string at moment to add on to the system. So not sure if the King was a issue with pv generation or the newer higher voltage setup is just that better and more efficient. The new setup has been running for 2 days so far and i will monitor over the coming week. Something seems weird with the King. Purely changing to 8S should not cause such a big difference.
March 19, 20242 yr today i had a brief chance to check on a sunny hot day with some cloud. max i seen was 1.96kw at 11am . put on 2 aircons and my projector tv quickly. total power consumption was 2.5kw. inverter set on sbu and i changed over to sub to double check.
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