Growatt Maximum Charge Current setting...

jsl10

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Thanks! I'll do that. Then wait until tomorrow to see if any change.
 

jsl10

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Oh... the inverter is hooked to the mains for grid power for when batteries are low. But I have that breaker off right now. Want to get the solar side of things working before adding in that factor.
 

jsl10

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Oh also... earlier when you said your firmware version was 511.3, did you mean 511.03? I assume probably just a typo but wanted to double check that I'm using the same exact one. Also, I just discovered that you can see the firmware version in the on-line Dashboard by hovering over the little 'i' after the "Device Serial Number" at the bottom. It's displayed as "Build Number". You probably already know but I didn't realize that before. Wish I had checked which firmware I was using prior to updating.
Yes 511.3, but can't find mine. Sorry
 

jsl10

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Some progress... After trying everything S.S. could suggest (including updating firmware, etc.) they advised that I switch to US2 (at least as a test). So I switched it to US2 with the following settings #2 = 150A, #11 = 40A, #12 = 46V, #13=54V, #19=57V, #20=56V, #21=44V. Immediately my solar power output more than doubled. They can't for the life of them figure out why the inverter was capping the Max. Charge Current (setting #2) to 50A. It's being suggested that the inverter might have a bad communications board and it was not communicating properly with the batteries. So that's where I'm at right now. Not sure what I'm missing out on with US2 vs Li battery type setting. At a minimum I guess it means that the inverter has no idea what's going on with the batteries other than the battery rack's voltage (i.e. each battery BMS is on it's own). At least this proves my solar array is capable of putting out a LOT more than it was before!
 

Darren67-72

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Well, the only thing I would suggest, setting 21 might be too low. What seems to happen when you are not using communication, is the inverter only uses voltage as a guide for the battery level, this is not the best way to measure the battery charge. Your bms will determine when the battery is at a low state of charge and may turn off the battery or even more if this happens say at night, when you are unaware.Then as the next charge cycle starts, the battery(s) that are off will not charge and the battery bank will be way out of balance.
There are a lot of post on here about balancing your lifpo batteries, and it can be troublesome.
 

Darren67-72

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Maybe, these is something we are missing...
You said setting #2 are you saying that it was reading 50?
This is the "updated problem" I talked about in my earlier post, that after my update this setting went to 180A which is too much for my inverter, but I don't use combined charging so I did not care.
Perhaps your inverter is limiting setting#2 because of your setting #11 maybe not. Weird things happen with little changes on these inverters.
 

Darren67-72

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If your interested, I'd be willing to go through your settings. I wished there was someone to help me when I first got my system. If not, I understand. Good luck.
There are a lot of people here, that share their time to help others. Glad to be a part of it.
 

jsl10

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Thanks for your continued thoughts on this very confusing problem! Let me describe to the best of my understanding. Prior to changing the battery type to US2, I would check the value of setting #2 (Max Charging Current) via the web Dashboard. I could never set this setting because in Li mode (setting #5) the inverter manages it (along with 19, 20, 21). When I'd look at it early in the day it might be set at 7A. Then later sometimes 18A. Eventually it would reach 50A and never go higher. This kept my solar energy draw maxed out at about 2600W (about 53V*50A). When we changed it to US2, we set #2 to 150A. Note that my solar array could ever go that high but it allowed the inverter to draw as much from the solar array as possible. Since no longer capped, I can see variations during the day and a gradual drop as the day gets on to evening. Today my maximum solar panel draw was at 6059W (86% of theoretical maximum) which translates to about 114A on the battery (well short of the 150A of setting #2 of course). This is less than 23A per battery. Grid A/C contribution is limited to 40A but even if that happens, the overall limit would be 150A (setting #2). At 150A and 5 batteries that's 30A per battery. Even if one battery was down it would only be 37.5A which is well below the per battery limit of 100A. S.S. support is wondering if maybe I have a bad communication board in the inverter or even possibly in my Master battery. If it was not "talking" to the battery properly it might of gotten incorrect information and would limit the setting of #2 to 50A. Hope I'm describing this correctly!

Thanks for offering to go through all the settings. I'll go out later and write them all down and post here. I SOOOO much appreciate yours and others help here. Seems like a great community of very knowledgeable people.
 

Darren67-72

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I don't mean to overwhelm you here but, there are settings on a growatt that can conflict with each other and/or your desired use. That is why I want to try to help with the settings.
Sometimes even a .1v change can cause some of the functions to not work.
 

jsl10

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No problem with overwhelming. I really appreciate the help! I like to learn things and then enjoy helping others as well. This mornings energy chart shows (see attached) the solar kicking in around 6:30am and the inverter probably using it to top off the battery. Then started a heavy load at 8:30am and watched solar energy come up and exceed the draw (as the sun got higher). This is pretty much exactly as I would expect. Even a dip as a heavy cloud went by. So no more of that dumb capped stair-step pattern. Only one thing seemed odd... when looking at the overnight battery soc chart it shows 100% all night (even though at first sun it did draw some power probably to charge). Before it would show a few percent drop just to keep the inverter alive (no external loads). Does staying at 100% all night keeping the inverter running seem right? Maybe the new settings changed what was defined as 100% full? Or, the new settings are charging the batteries a bit more than before. Thoughts? Anyway, here are ALL my inverter settings below. Thanks for looking them over.

Inverter Settings:

1: Sbu
2: 150A
3: APL
4: ---
5: US2
6: Lfd
7: ---
8: 240V
9: 60Hz
10: ---
11: 40A
12: 46V
13: 54V
14: SNU
15: bOF
16: LON
17: AON
18: ---
19: 57V
20: 56V
21: 44V
22: 001
23: dl5
24: 58.4V
25: 060
26: 061
27: 001
28: dl5
 

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  • Solar Energy Chart 08.JPG
    Solar Energy Chart 08.JPG
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Darren67-72

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I don't think the inverter, just staying on overnight would consume enough power to take your batteries off 100% but, I'm unsure what is going on at night. You don't use any power at night? That is why most people get batteries, to get them through the night. You don't have to, some like to keep full batteries for power failures.. I get that.
I think setting #14 is what has got things working differently than you want. Setting 14 as "SNU" uses BOTH utility and solar to charge your batteries at the same time during the day. Using this setting can be confusing, and explains why you reference setting #2.
Before I can offer suggestions, I guess I should have asked what your using this setup for? What I mean is, if you want it for just backup power source, or for off grid type use, or both with utility savings, or whatever you want?
The #14 setting is the one that will cause the most problems, due to the complexity of using both grid and solar to keep batteries charged, and at what point does the battery cycle start and stop and with which power supply at what time of day/night.
 

Darren67-72

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Although it might explain why your batteries are 100% in the morning, because utilities were charging them all night.
What I dislike the most with this setting is, it works with settings #12 and #13 and there are times when the sun is up and you have good solar but your still consuming utility power. Now your batteries are charged by noon (and you paid for some of it with grid power) and you have the rest of the day of good solar, yet you are not using it... because your batteries are charged.
This is a big reason people buy solar and are disappointed when their electricity Bills are the same as before they got solar. (Not to mention conversion losses).
 

Darren67-72

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If you would indulge me, what dip switch setting are you using on your master battery? (All down?) and if you think there might be a communications issue with that battery, you could just trade out another battery and make it your new "master" then you would solve that question, without the troubles of mailing or warranty or changing boards..... you get the point.
 

jsl10

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I believe the 12K inverter draws 150W when ON and no other load. Over 12 hours that's 1.8kWh. Anyway, I've read here that it's common for the SoC to be stuck at 100% since without BMS communications, the inverter won't know what the SoC is. So maybe that's to be expected with the US2 setting. Tomorrow I'm going to try to move the battery master to the bottom battery (and re-set the dip switches accordingly). This would show if there was a communication board problem in the battery (vs the inverter). At this point I wouldn't be surprised if simply running now in US2 mode has changed things to make Li mode work! I seem to say who knows a lot these days! :)

Good catch on setting #14. Your right of course, I only want grid charging when it's really needed! I'll change that to CSO. But I did have grid turned off up to now though. So maybe that hasn't made any difference or the inverter simply didn't like the SNU setting without grid power. Who knows. But either way, that setting should be CSO right?

Regarding my usage... On normal days I'll be charging the plug-in hybrid once at night (didn't need a charge the other night) and once during the day. Each car charge takes anywhere from 5-12kWh depending on how low it is. A refrigerator and a stand-alone freezer will also run daily (not plugged in yet). The inverter output is also back-fed into the home's "generator" panel for powering most of the home but only when we have a power failure. The home "generator" panel also powers the well pump (thus the high surge requirements on the inverter). During a power failure and we are powering the home, car charging will take a low priority. Hope this all makes sense and is reasonable. Let me know what you think. I'll also let you know if anything changes with changing which battery is master.
 

Darren67-72

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Setting 14 at CSO is fine, although it will still charge your batteries at night. This is like running a electric dryer continuously. It is also going to keep your batteries full charged. (Best it can) and they will be 100% every morning.
For best cost savings "OSO" is the setting you would want.
The 150w draw would have still been recharged by the setting 14. And if not used at night, stand by, mode would use less.
I also mentioned that if you stay on "US2" the batteries will likely get out of balance, and you don't want that. This will not happen in CSO (setting 14) because your paying grid to keep them charged, and they wont get out of balance, if you keep them full charged all the time.
Anyway, at this point, you could try the "Li" setting again.
 

jsl10

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Here is my thinking on setting 14 (I could very easily be wrong!)... first the manual says that the setting is only used when in "line" (utility), standby, or fault mode. It says when in "battery mode" only solar is used. So with setting 1 at "SbU" does setting 14 even matter UNLESS the battery drops below setting 12 (i.e. when it goes off battery mode and back to utility mode)? Wow, talk about a confusing setting! Now that I have utility power to the inverter energized (it wasn't before) I can do a test at night to run a load that will drop the battery (but not below setting 12) and see if it shows any utility power used (i.e. anything in "Imported from Grid". So far my "Imported from Grid" has been zero this entire time.

With more reading here in the forum, I've seen others describe the stuck at 100% soc issue. General feeling is that when not in Li mode, without any BMS communications, the inverter only "sees" the battery voltage . So given that a lithium battery bank can have a very flat voltage at the top end of full charge the soc stays at 100% for a long time. This makes sense to me. It also got me thinking that since the soc was so accurately being reflected before (I could watch each % drop at night when on a big load) the inverter MUST of been communicating ok with the master battery BMS. So maybe the master wasn't seeing the other batteries and we're back to our original thought that the inverter only thinks I have one battery! I'm going to swap the master to the bottom battery this morning and see what happens. I'll let you know.
 

Darren67-72

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Wow, you are really quite smart about all this, really!!! It took me a long time to learn all this, and still not an expert by any means.
I don't think changing the master battery is going to do anything but, worth a try. I still think it's a setting but, I really don't know.
You very well could be right on the communication, I just don't think so.
The oso setting cost nothing to try, just my opinion. For what its worth.
 

jsl10

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Smart? Don't know about that. But prior to retiring I was a software engineer so pretty use to debugging things. I did switch setting 14 to CSO.

Well... I did the test (swapping which battery was master, changed all dip switches accordingly and changed battery type back to Li). And guess what... solar power is back to being the way it was before! So as you suspected, it didn't matter. US2 works and Li doesn't draw required power from solar panels. See attached chart. In it you can see where in the morning the solar output raised up to 2600W (probably to top off the battery from over night). Then I shut things down for the test and changed battery type back to Li. I then turned on a couple space heaters as a load. You can see in the chart that solar won't come up to meet demand! Of course, with BMS communications back, the battery SoC is working again. The battery has dropped from 100% to 97% with this load even though there is plenty of solar if it would just use it!!! I'm getting frustrated if you can tell.
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