Growatt spf Not Seeing PV In The Morning

[Wycito]

This has happened to me a few times, generally after a bad solar day (yesterday was quite rainy in south western Ontario, in the morning, the solar does not engage, even after the sun is fully up.
I got a SFF 8000T DVM-MVP, with a max solar voltage of 250v, 3s7p 300w Silfab panels, charging my 35kw custom made lithium-ion pack, so I dont think it is the solar voltage spiking.
Do see in my solar assistant a voltage spike at 2300 of 200v, still not reaching the 250v my inverter can use.

My solution so far as been to disconnect the solar via DC breakers, and wait until the capacitors on the solar side discharge to under 40v, then turn it on, fixes it every time, no need to shut down the inverter.

has any conclusion has been drawn into what may cause this?

 

[Zwy]

Have you tried updating the firmware?

 

[BekimV]

Have you tried updating the firmware?

Where can the firmware be found?

 

[Zwy]

Where can the firmware be found?

For which inverter? Make/model?

EG4 products are here. https://eg4electronics.com/downloads/

Growatt: https://watts247.com/docs/growatt-firmware-where-to-find/

 

[BekimV]

For which inverter? Make/model?

EG4 products are here. https://eg4electronics.com/downloads/

Growatt: https://watts247.com/docs/growatt-firmware-where-to-find/

Growatt 3000 lvm es European version 220v. Im not sure if this firmware is compatible with the european model which is 220v 50Hz. I checked the Growatt official site and there is no firmwares to download.

 

[Zwy]

Growatt 3000 lvm es European version 220v. Im not sure if this firmware is compatible with the european model which is 220v 50Hz. I checked the Growatt official site and there is no firmwares to download.

The GW 3000 ES for Euro is not LVM, it is similar to the SPF 5000 ES. I ran across this thread and you should try emailing the mentioned people in this post. https://powerforum.co.za/topic/1012...vm-24-firmware/?do=findComment&comment=106360

Amos has this page but I do not see anything for the GW 3000 ES. https://www.amosplanet.org/firmware-download-for-off-grid-inverter/

 

[apctjb]

Just saw this thread, so coming late to the game. The problem with Growatt SPF inverters not starting MPPT charging the next day appears to be normal operation for these inverters. It occurs only if the day before battery voltage reaches absorption setpoint, and the loads are small relative to PV input. The inverter will go into float for a period of time and then stop charging (this is how they operate when charging from AC, they do not stay in float when charging is done.) The next day after this occurs charging will not resume until batter voltage falls to approximately 52.5 (on 48V version) which starts a new charging cycle. Unfortunately this charge resumption setting (52.5V) is not user settable.

My work around for this issue is to run some larger loads early in the day which typically will pull the battery voltage down and MPPT charge will then resume starting a new charge cycle.

Growatt has suggested various firmware updates but none have resolved the issue. The firmware update specifically intended to fix the MPPT timeout issued crashed my MPPT tracker altogether (no solar charging under any circumstance). Luckily I was able to update firmware to the original firmware that came with the inverter and this got the MPPT working again.

So if anyone has a sure fire way to correct this issue, would love to hear it.

 

[Zwy]

My SPF3000TL LVM has float set 0.5V below bulk, and yes, it is in the settings. It will start charging if battery voltage drops below float. Doesn't matter if AC charging or from PV. It has always worked this way, I just finished using it for 2.5 weeks on a trip. Still works the same.

 

[timselectric]

I've never had the charging issue, either.
With any of my 5000ES units.

 

[apctjb]

I've never had the charging issue, either.With any of my 5000ES units.

Thats great, perhaps the problem is just with the SPF-LVM models, the ES units are of a newer design.

 

[apctjb]

Below is typical operation on my system. You can see charging does not start until 9-10in the morning after running larger loads (AC mini splits) to pull down the voltage. Problem got worse when I added an additional 15kwh of battery capacity, because the voltage does not fall as quickly. Perhaps if my inverters could talk with my battery bank it would resolve the issue, but my Daly BMS does not talk with Growatt...

 

[timselectric]

Thats great, perhaps the problem is just with the SPF-LVM models, the ES units are of a newer design.

It seems to be a sporadic issue, not all LMV models have the issue.
Could be installation or settings specific.

 

[apctjb]

It seems to be a sporadic issue

Yup, sometimes I go months without the issue, and then it shows up. Seems to be a function of loads, battery capacity and charging rate. I can create the problem simply be dialing back loads on a sunny day so batteries are fully charged by midday and go out of float mid afternoon. Next day charging will not resume until battery voltage falls. Absorb, float and terminate is the charging algorithm built into these inverters.

 

[timselectric]

Yup, sometimes I go months without the issue, and then it shows up. Seems to be a function of loads, battery capacity and charging rate. I can create the problem simply be dialing back loads on a sunny day so batteries are fully charged by midday and go out of float mid afternoon. Next day charging will not resume until battery voltage falls. Absorb, float and terminate is the charging algorithm built into these inverters.

What are your bulk and float settings?
It could possibly be avoided by changing them.

 

[apctjb]

What are your bulk and float settings?

currently 54.5A, 54FI have played around a lot with these settings over the past 2 years, have yet to find any that avoid the issue (and don't overcharge individual cells).

Thx

 

[timselectric]

currently 54.5A, 54FI have played around a lot with these settings over the past 2 years, have yet to find any that avoid the issue (and don't overcharge individual cells).

Thx

Those are kinda low, in my opinion. But, in relation to each other. I don't see anything that would cause the issue.

 

[Zwy]

currently 54.5A, 54FI have played around a lot with these settings over the past 2 years, have yet to find any that avoid the issue (and don't overcharge individual cells).

Thx

I run up into the knee area. I think the reason you do not see charging start is at 54V float, the cell voltage is 3.375 which is basically about where the charge/discharge curve goes flat. Even with the bulk at 54.5V, the cells will not have absorption and balance occur as that is 3.40V per cell. I know we have had this discussion in the past. You want to use conservative settings to extend cell life but not getting above cell balancing voltage may be causing more damage than running up over 3.4V. Some cells may be 3.30V while others might be 3.6V. At 3.375V per cell, I doubt your cells will be balanced well.

My batteries in my house are set at 55.5V float and bulk at 56.0V. In my truck camper, it is close to 28.0V for bulk and float at 27.5V. Both of these float voltages get the cells above 3.4V and this is where my bms's are set to begin balancing.

If your cells don't balance well at higher voltages then it might be wise to use an active balancer.

 

[apctjb]

I think the reason you do not see charging start is at 54V float, the cell voltage is 3.375 which is basically about where the charge/discharge curve goes flat.

Agreed; Growatt SPF appear to have been designed for Lead Acid where the voltage swing is much larger than LiFePO4, especially with larger battery banks. As you mention I don't like running mine as high as you suggest. Have you watched the video from "myoffgrid" garage that dives into this topic. Based on capacity testing at various float voltages he suggest 54V brings LiFePO4 very close to 100% and avoids runaway cells.

I don't know, just cautious.

 

[Rednecktek]

So quick question, and maybe I missed it, but where d I find the most updated firmware and ShineBus downloads?

 

[Zwy]

Agreed; Growatt SPF appear to have been designed for Lead Acid where the voltage swing is much larger than LiFePO4, especially with larger battery banks. As you mention I don't like running mine as high as you suggest. Have you watched the video from "myoffgrid" garage that dives into this topic. Based on capacity testing at various float voltages he suggest 54V brings LiFePO4 very close to 100% and avoids runaway cells.

I don't know, just cautious.

Andy runs active balancers and also an absorption period higher than float. It is during the absorption that balancing takes place.

Like I said, if you are not getting above 3.4V per cell for balancing to occur, you might be doing more damage to cells than if you did charge to a higher voltage. You don't show your cell voltages but I would guess some read higher than others. Plus pack capacity could be reduced considerably as lower cells are in the flat part of the charge/discharge curve.

Ensuring all cells get above 3.4V is not going to degrade the cells faster than calendar aging. I run less than 95% SOC and it works quite well.

As you are a fan of Andy's, then possibly you missed this video.