Help wanted-Growatt/MPPT users.

[Joe BoyKey]

Had share ground on growatt and makeskyblue, caused makeskyblue to over wattage bad and was trying to overcharge batteries

 

[apctjb]

Rewired this morning, and now testing. Stay tuned.....

 

[apctjb]

Rewired this morning, and now testing. Stay tuned.....

Unfortunately did not resolve the issue. When operating in single phase parallel (setting 23 to PAL), one inverter does all the solar charging and then the next morning neither resumes charging unless I power down/up resetting the system. At this point I have tried every conceivable setting without luck....

 

[Gaze]

I have a single Growatt 3000. Everything works except it will not charge battery past 54.0v (which coincidentally is the default value for this unit per the manual). It stops charge at 54v regardless of upper charge voltage limit (setting #13), bulk charge or float settings. Although my custom settings are apparently saved/accepted, the unit seems to disregard them and invariably stops at 54v. Maddening. Can't get the full potential of the battery which has an upper safe pack limit of 58.8v. On the other hand, lower voltage limit settings it has no problem.

Any ideas what I can try?

 

[apctjb]

It stops charge at 54v regardless of upper charge voltage

What setting are you using for setting 5, battery type. If you are using Use2 it locks charging voltage to 54.

 

[Gaze]

"locks charging voltage to 54", wonder why it would do that

Originally I was testing this set to Use2. Someone suggested (I think in this or another thread of yours) to try Use, which I did a little while ago with no joy. I'm going to try again in the morning after a full reset.

BTW, can you tell me 1) how to do a full reset 2) where to check my firmware version 3) thanks for letting me know, but where did you find the info that it locks charge at 54v?

 

[schmism]

I have mine configured to charge to 57.0 v for my NMC and it does. No issues with operation on my dual parallel setup. I do have my array split in 2 so each unit has its on array per the instructions.

 

[Gaze]

I have mine configured to charge to 57.0 v for my NMC and it does. No issues with operation on my dual parallel setup. I do have my array split in 2 so each unit has its on array per the instructions.

Nice. Then there's hope. I have NMC as well.
Would you be so kind as to post your settings? Especially #5, 12, 13, 19, 20, 21
Thanks

 

[Manyaka]

Hello, we have installed a few systems with Growatt 3000 inverters and experienced the same problem of not starting to solar charge in some mornings in 3 systems with relatively low loads compared to the LiFePo4 battery bank installed. All systems are using 2 inverters. In 2 of the systems the problem was resolved by having solar panels connected to both inverters (before, only one of the two inverters had solar panels connected) (no idea why this resolved the issue). Now we have another system with the same issue, but it already has solar panels connected to both inverters. We just increased the float voltage to the same level as the bulk voltage at 55V and are waiting to see whether this might resolve the issue.

 

[apctjb]

We just increased the float voltage to the same level as the bulk voltage at 55V and are waiting to see whether this might resolve the issue

I have PV on both inverters, and the inverters are paralleled at 120V. On a daily basis one inverter will stop charging around midday, the other will continue to charge. Occasionally both will stop and sometimes not resume for a day or so. Only when loads are low. I suspect, although have not been able to verify that after being in float for a period of time (how long unknown) the inverters go out of charge mode. They do not resume until battery voltage or SOC triggers them to resume (what these setting are remain a mystery.) My SOC always shows 100%, which I suspect is because with LiFePO4 batteries my system voltage is very constant varying between 52 to 54 V on most days.

I am very happy with my Growatts, really amazing inverters for the price, but if anyone knows the secrets of what triggers them to stop and resume charging I am curious to know....

 

[Manyaka]

I have PV on both inverters, and the inverters are paralleled at 120V. On a daily basis one inverter will stop charging around midday, the other will continue to charge. Occasionally both will stop and sometimes not resume for a day or so. Only when loads are low. I suspect, although have not been able to verify that after being in float for a period of time (how long unknown) the inverters go out of charge mode. They do not resume until battery voltage or SOC triggers them to resume (what these setting are remain a mystery.) My SOC always shows 100%, which I suspect is because with LiFePO4 batteries my system voltage is very constant varying between 52 to 54 V on most days.

I am very happy with my Growatts, really amazing inverters for the price, but if anyone knows the secrets of what triggers them to stop and resume charging I am curious to know....

Have you tried to set the float voltage so low that the inverter would rarely enter the float charging mode - for example 51V given the battery is LiFePo4 51.2V? Or have you tried both bulk and float at 55V, so at night the voltage drops significantly below that?

 

[apctjb]

Have you tried to set the float voltage so low that the inverter would rarely enter the float charging mode - for example 51V given the battery is LiFePo4 51.2V? Or have you tried

Yes to both. Problem with setting the float low is once bulk has been reached the voltage naturally stays above float so the inverters stop charging altogether. My guess is the settings/software were originally designed for the voltage charging curve of lead acid , not for the very flat curve of LiFePO4.

 

[Zwy]

Have tested it with UTI, SOL or SBU , doesn't appear to have any impact when utility is not present. Ian suggest I leave it at UTI

It should be SBU or SOL. UTI would draw from grid first if present unless you're using this as backup to grid. Sometimes I think Ian has some weird advice.....

SOL would be PV first, battery if PV can't supply enough for load, and grid last. SBU is PV, then battery, then grid.

 

[debron55]

Trying to troubleshoot an issue and hoping that other Growatt/MPPT owners might be able to help.

Does anyone know what triggers the inverters to stop solar charging after reaching float voltage and what triggers them to resume charging?

Is charge termination and resumption based on voltage setpoints, elapsed time, SOC, or something else and are they user adjustable?

The issue I am observing is that once PV charging stops after float voltage is reached it can take a long time for charging to resume, sometimes more than a day. I have a 560AH LiFePO4 battery and loads are modest so voltage is not changing much. But rather than drawing energy from the battery it would be nice to have solar meeting the load, but that only happens when the inverters are in charging mode. Once they stop charging they draw energy from the battery regardless if solar is available.

I see similar behavior - not so much the not charging in the morning. But at / around 1 - 2 pm during sunny days the batteries are full and the charge controller shuts off and the unit flips into battery consumption mode.

If I reboot the unit.. Turn off the inverter and flip the battery disconnect and start it back up. My unit starts charging the batteries again and if I flip the ac supply breaker (simulating a loss of the grid) the unit will use solar to power my nominal load while charging the batteries. I posted an article in this forum called Growatt - Odd Behavior and included a youtube video link.

 

[debron55]

It should be SBU or SOL. UTI would draw from grid first if present unless you're using this as backup to grid. Sometimes I think Ian has some weird advice.....

SOL would be PV first, battery if PV can't supply enough for load, and grid last. SBU is PV, then battery, then grid.

SOL would be PV first, battery if PV can't supply enough for load, and grid last. SBU is PV, then battery, then grid. those seem like the same thing. pv first , battery then grid..

 

[schmism]

Nice. Then there's hope. I have NMC as well.
Would you be so kind as to post your settings? Especially #5, 12, 13, 19, 20, 21
Thanks

Sorry didn't see this months ago.

5 -- use
12 - 47.0
13- 52.0
19 - 57.0
20 - 55.0
21 - 45.0

1- SBU
14 - OSO

Given the above settings, I run out of battery over night - hit 47v transition to grid. Run on grid till sun comes up and inverters charges battery to 52v then the system switches to off grid. (between 8am and noon depending on sun/season) I'll continue to charge and run the critical loads panel all day, about 4pm the PV stops being able to produce enough for all the loads and I slowly start drawing battery as needed. Ill run off battery till I hit 47v and we start over.

The only feature I wish they would add is a storm warning button. An option you could trigger that would tell the unit to transition to grid, and charge the battery to max (set a timer for like 8 hrs after which you transition back to whatever your normal settings are) if your anticipating going into a potential grid out condition. (pending Ice storm, severe thunderstorm, hurricane is going to hit etc)

 

[Zwy]

SOL would be PV first, battery if PV can't supply enough for load, and grid last. SBU is PV, then battery, then grid. those seem like the same thing. pv first , battery then grid..

Yes, that is basically what the manual says. One then asks, why have 3 different settings when only 2 were really needed? Both SOL and SBU will switch to grid if the value in setting #12 is hit.

My guess is how the GW handles loads during periods of high and low PV array production when the inverter is on. Only a guess but only explanation I could see for having the 2 settings appear to be the same.

Take this post for example: https://diysolarforum.com/threads/growatt-odd-behavior.22696/post-270444

What happens is battery hits full charge SOC and the unit stops charging but runs off battery power instead of utilizing the PV array production. Would SOL work better than SBU or vice versa and eliminate the problem? If the settings are changed and no difference noted, then really there is a problem with either the unit, the software/algorithm in the MPPT or the PV array isn't putting out enough power at the time it occurs. Given the 1 pm to 2 pm time frame in that post, I doubt it is the 3rd scenario.

 

[Joe BoyKey]

21 is float. Ie... CC charges battery to bulk, shuts down solar, drops voltage down to (21) setting and resumes solar to carry loads and keep batteries at (#21) float voltage, this is what my SPF-6000T-DVM does every day. It takes about 30 minutes depending on load, My batteries are Lifepo4 and don't require Equalization or float so 54.6 is a good load carrying voltage, I use SBU only unless batteries get low, then switch to UFI till sun comes out, Joe.

 

[apctjb]

My 2 parallel Growatt-3000 operate somewhat differently with one inverter stopping charging soon after reaching setpoint 19 (Bulk Setpoint), the other continues to supply solar following the load. On some days, if loads are small, both will stop charging altogether. When they resume varies, sometimes later the same day, sometimes the next day and sometimes it takes a couple of days. What triggers resumption is still a mystery but it appears to be when voltage falls below a certain value which is not directly (perhaps indirectly) user setable. I have 32kwh of LiFePO4 battery so if loads are small it can take a while for battery voltage to drop from say 56 to 52.5 (which is where I have observed charging resuming). It would be nice if the resume charge setting was user adjustable of if setting 14 is solar only that the MPPT charger stays in float and does not disconnect. I have played with all setting combinations, the only thing that appears to have an impact is setting 19.

 

[SPockets14]

My 2 parallel Growatt-3000 operate somewhat differently with one inverter stopping charging soon after reaching setpoint 19 (Bulk Setpoint), the other continues to supply solar following the load. On some days, if loads are small, both will stop charging altogether. When they resume varies, sometimes later the same day, sometimes the next day and sometimes it takes a couple of days. What triggers resumption is still a mystery but it appears to be when voltage falls below a certain value which is not directly (perhaps indirectly) user setable. I have 32kwh of LiFePO4 battery so if loads are small it can take a while for battery voltage to drop from say 56 to 52.5 (which is where I have observed charging resuming). It would be nice if the resume charge setting was user adjustable of if setting 14 is solar only that the MPPT charger stays in float and does not disconnect. I have played with all setting combinations, the only thing that appears to have an impact is setting 19.
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My brother is having the same issue. One inverter will continue to charge and carry load...the other one stops charging all together. Sometimes in the mornings one inverter will simply not start charging. Only way to get it to start charging again, seems to be to turn it off and back on