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Growatt LV verses LF split phase

Andyb

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Aug 29, 2020
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been watching the youtube channel a while and really enjoy the content, the clear and concise explanations and the authentic enthusiasm. Was about to purchase a growatt 50/48 LV series split phase but stumbled on the LF version. What is the diff? Seems like LF has great output at 6k. Its for my large RV with 2 ACs on the roof.
 
The Growatt units have poor surge capability. Running 2X A/Cs (assuming you have mega-batteries and about 4kW of solar) would put a strain on it, particularly during start surge.

A Sigineer APC6048 has a 18kW surge and is capable of 120V single or 240V split.

Since you presumably have a 50A RV plug, the two A/Cs are on separate legs. You will either need to supply split phase to each leg as the 50A RV plug does, or you'll need to jumper L1 and L2.

I can just run 2X A/C (staggered start) with my victron Quattro 4k/48 with L1 and L2 jumpered.
 
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Assuming they are i may not run them at the same time and at worst they are not on same thermostat thus starting at different times, what is the diff between and LV and an LF?
 
Hey. I’m looking at the LF series also. There is essentially no information out on this series except for a brochure and postings of units for sale on eBay. I have corresponded with the seller and he affirms the LF series is true split phase. It does nor suffer from the poor surge performance of the LV series. Gotta say that seller has a solid history, excellent feedback, and some great prices on a range of solar products. I think I am going to pull the trigger on the 6kw SPF6000TDVM.
 
I hear you and am cautious. It is perplexing that the LF model does not show up on the Growatt website. The eBay seller I will say has a very high rating and has been active for years. Will do the due diligence before spending my money! Will see what Growatt says and report back.
 
So here’s what I learned. The Growatt SPF6000TDVM Is identical to the Sigineer M6000L-48SP. Identical manuals except the Growatt has their logo on the manual. And Growatt pointed me to the unit information on their website. So one is just a re-label of the other. Still need to confirm both are true split phase. The manuals don’t indicate that but numerous sellers claim that is the case.
 
Short update. Confirmed the Growatt SPF6000TDVM is indeed true split phase and they are the OEM. 2kW solar panels purchased, inverter installed, 17 Basen 120 A-hr LFP prismatic cells on a boat between US and China, Daly 180 A-hr BMS (Wfi module included) arrived, and about 2/3rds of the AC wiring installed. System will nominally power my pump house (240V well pump, 330’ deep) and also serve as our emergency power backup. Enough power if we have to ride out a hurricane power outage - assuming of course we get through the storm in one piece!
 
Hey B, did you install your Growatt 6000t inverter yet? I have mine up and running and like it so far but only concern is the loud humming coming from the unit when the charge controller is activated. What is you experience so far?
 
Hey Damian. Not quite there yet. My 16 120 A-hr LFP cells don’t arrive from China till the end of this week. Can’t say for sure if you have a problem, but I have read several different sources that note these units are pretty noisy. Let me know if you figure something out. With my work schedule, I suspect I’m still 2 weeks from getting up and running. Will post an update when I get there.
 
Hey B, did you install your Growatt 6000t inverter yet? I have mine up and running and like it so far but only concern is the loud humming coming from the unit when the charge controller is activated. What is you experience so far?
Hey Damian. I’m sorta up and running. Not hearing that humming noise you mentioned When the charge controller is operating. I do have a high battery voltage fault I don’t understaNd as the battery is sitting at 53V (multi meter, shunt, and Growwatt all say the same). Any idea what is causing my fault? Also can you tell me what battery settings you set in your Growatt?
 
what is the diff between and LV and an LF?
LF is a low frequency transformer design. The advantage of the low frequency inverter is its simple structure, and various protection functions can be realized at a lower voltage. Because there is a power frequency transformer between the inverter power supply and the load, the inverter operates stably, reliably, with strong overload capacity and shock resistance, and can suppress higher harmonic components in the waveform. However, the power frequency transformer also has the problems of large size, bulkiness and high price, and its efficiency is also lower than that high frequency inverter, and the no-load loss is higher.

LV is high frequency design. The high-frequency inverter uses a small, light-weight high-frequency magnetic core material, which greatly improves the power density of the circuit, so that the no-load loss of the inverter power supply is small, and the inverter efficiency is improved. The peak conversion efficiency can reach more than 90%. High-frequency inverters is not suitable to connect inductive loads, such as water pumps,air conditioner,refrigerators etc.
 
Hey Damian. I’m sorta up and running. Not hearing that humming noise you mentioned When the charge controller is operating. I do have a high battery voltage fault I don’t understaNd as the battery is sitting at 53V (multi meter, shunt, and Growwatt all say the same). Any idea what is causing my fault? Also can you tell me what battery settings you set in your Growatt?
I’m also using lifepo4 batteries and have it set on “Use” : Bulk charge 54.4 and float at 54.2. my cut off is 47.8. I haven’t experienced this problem with over voltage fault however it seems that the issues experienced with different owners are random. I wish there was more info out there on this model and how to trouble shoot or know when the unit is defective. Do you have it on the lithium setting? If you do then you will surely see a fault
 
I’m also using lifepo4 batteries and have it set on “Use” : Bulk charge 54.4 and float at 54.2. my cut off is 47.8. I haven’t experienced this problem with over voltage fault however it seems that the issues experienced with different owners are random. I wish there was more info out there on this model and how to trouble shoot or know when the unit is defective. Do you have it on the lithium setting? If you do then you will surely see a fault
 

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any updates on the performance? I am thinking of doing a very similar setup with the Sigineer M6000L-48SP and am wondering what people think.
 
Way late on a response but here is an update on my Growatt SPF6000TDVM. The system is up and running and I've had 3 blissful weeks of continuous operation finally. The Growatt is paired with a DIY 48V 16S 120 Ahr LFP battery pack operating with a 150Ahr Daly Smart BMS and a 2 kW solar array. I use the system only to run my well pump and it is also intended to provide emergency power eventually (we live in hurricane alley south of Houston).

The Growatt SPF6000TDVM is incredibly inexpensive but it has its limitations. Long story short is it will not handle what I consider "nominal" behavior from a battery pack - namely if the battery shuts down either because of under voltage or over voltage. I had both happen to me as I sorted out issues with one poor behaving cell in my 16S pack.

The first issue was with a low voltage on the battery pack. The lower capacity cell would hit the “low cell voltage” set point on my BMS and the BMS would do the correct thing and isolate the battery pack. The inverter would stop inverting and throw a low battery voltage fault. At the time this happened, I was still figuring out the Growatt, and I had not enabled the “switch to grid power” when the battery voltage goes low. I do note if you do not have grid power, well you don’t even have that option. So what would happen is the battery pack would eventually enable when the offending cell voltage rose about the cut-off voltage. And since the inverter DOES NOT stay in fault mode (this is the first major short-coming of the Growatt inverter) , the inverter would then do its thing and start inverting, and the cycle would repeat. Well this happened in front of my eyes for about 3 or 4 cycles, and my main inverter board put on a very entertaining fireworks display that include loud pops and lots of magic smoke! Now mind you I had not figured out all of this at the time it happened.

I bought my Growatt from Signature Solar (https://www.signaturesolar.us/) and they are great – they sent me a replacement set of boards at NO COST, since at this point I was just thinking the inverter crapped out. They stand behind their products and they took care of me. The Growatt unit is relatively easy to work on and I got the two boards replaced, turned it on, and I was back in business. This time I made sure the “switch to grid power” was enabled if the battery went low.

So now the fun in the other direction – This time it was a high voltage issue. The inverted would shut down during charging when the same low performing cell went above the “high cut-off voltage” set point and the BMS isolated the battery. It would go into a “high voltage” fault since the battery was disconnected and the array was sending all that glorious solar energy to the battery. But that fault state is "soft" (like with the low voltage fault this is the second major shortcoming of the Growatt inverter) and the unit will try to restart charging if the battery voltages drops below the “maximum voltage” set point. When the offending cell voltage would drop (like LFP cells do after charging is removed), the BMS would revert to enable, and the cycle would repeat. After about 5 cycles of doing this, my inverter main board promptly blew magic smoke again from several components on the PCB (less than the last time but still fatal).

So now I was finally figuring out I had one lower capacity cell in my 16S battery pack. I called Signature Solar, shelled out $250 for another set of boards, got them installed, and fired the unit back up. This time I set up inverter operation well inside of the published limits for LFP cells (2.5 V low and 3.65 V high). I set the “low voltage switch to grid” set point at 49.2V (3.075 V/cell) and the high voltage end of charge to 54.6V (3.4125 V/cell). I’ve been tweaking a bit on those two set points (plus the float voltage), to try and ensure I get 80% capacity out of my pack whether it is a bright sunny day, or something less.

So I’m up and running now and the 2kW system is performing well. Except for 2 exceptionally cloudy days, it’s been providing all of my well-pump power. I will say the inability to survive what I consider to be routine behavior of an off-grid solar power system (battery disconnecting due to low or high voltage), is a major short-coming of the Growatt LF series. You will always have to be checking your system as it ages to make sure it does not get into either a low-voltage or high-voltage situation because if it does, the unit will fail. I am fortunate that I have reliable grid power, but others using this unit as primary power will have pay close attention. I will say, the $1200 cost (roughly 1/5 of say a Sol-Ark 8K), may make this worth the pain for many folks (myself included at least for now).
 
It seems to me that the clash is between the inverter battery management and the BMS. And some beginners trial and error.
Will P has mentioned that if all batteries are new and equal that a BMS is not needed. This is something that seems logical, but wondering if anyone has tried this out in real world testing. In the initial top charge testing on the individual cells the bad one may have shown up before assembling the battery.

Also noted that you don't have any binding or compression on your cell bank. Is there a reason for this?
 
Way late on a response but here is an update on my Growatt SPF6000TDVM. The system is up and running and I've had 3 blissful weeks of continuous operation finally. The Growatt is paired with a DIY 48V 16S 120 Ahr LFP battery pack operating with a 150Ahr Daly Smart BMS and a 2 kW solar array. I use the system only to run my well pump and it is also intended to provide emergency power eventually (we live in hurricane alley south of Houston).

The Growatt SPF6000TDVM is incredibly inexpensive but it has its limitations. Long story short is it will not handle what I consider "nominal" behavior from a battery pack - namely if the battery shuts down either because of under voltage or over voltage. I had both happen to me as I sorted out issues with one poor behaving cell in my 16S pack.

The first issue was with a low voltage on the battery pack. The lower capacity cell would hit the “low cell voltage” set point on my BMS and the BMS would do the correct thing and isolate the battery pack. The inverter would stop inverting and throw a low battery voltage fault. At the time this happened, I was still figuring out the Growatt, and I had not enabled the “switch to grid power” when the battery voltage goes low. I do note if you do not have grid power, well you don’t even have that option. So what would happen is the battery pack would eventually enable when the offending cell voltage rose about the cut-off voltage. And since the inverter DOES NOT stay in fault mode (this is the first major short-coming of the Growatt inverter) , the inverter would then do its thing and start inverting, and the cycle would repeat. Well this happened in front of my eyes for about 3 or 4 cycles, and my main inverter board put on a very entertaining fireworks display that include loud pops and lots of magic smoke! Now mind you I had not figured out all of this at the time it happened.

I bought my Growatt from Signature Solar (https://www.signaturesolar.us/) and they are great – they sent me a replacement set of boards at NO COST, since at this point I was just thinking the inverter crapped out. They stand behind their products and they took care of me. The Growatt unit is relatively easy to work on and I got the two boards replaced, turned it on, and I was back in business. This time I made sure the “switch to grid power” was enabled if the battery went low.

So now the fun in the other direction – This time it was a high voltage issue. The inverted would shut down during charging when the same low performing cell went above the “high cut-off voltage” set point and the BMS isolated the battery. It would go into a “high voltage” fault since the battery was disconnected and the array was sending all that glorious solar energy to the battery. But that fault state is "soft" (like with the low voltage fault this is the second major shortcoming of the Growatt inverter) and the unit will try to restart charging if the battery voltages drops below the “maximum voltage” set point. When the offending cell voltage would drop (like LFP cells do after charging is removed), the BMS would revert to enable, and the cycle would repeat. After about 5 cycles of doing this, my inverter main board promptly blew magic smoke again from several components on the PCB (less than the last time but still fatal).

So now I was finally figuring out I had one lower capacity cell in my 16S battery pack. I called Signature Solar, shelled out $250 for another set of boards, got them installed, and fired the unit back up. This time I set up inverter operation well inside of the published limits for LFP cells (2.5 V low and 3.65 V high). I set the “low voltage switch to grid” set point at 49.2V (3.075 V/cell) and the high voltage end of charge to 54.6V (3.4125 V/cell). I’ve been tweaking a bit on those two set points (plus the float voltage), to try and ensure I get 80% capacity out of my pack whether it is a bright sunny day, or something less.

So I’m up and running now and the 2kW system is performing well. Except for 2 exceptionally cloudy days, it’s been providing all of my well-pump power. I will say the inability to survive what I consider to be routine behavior of an off-grid solar power system (battery disconnecting due to low or high voltage), is a major short-coming of the Growatt LF series. You will always have to be checking your system as it ages to make sure it does not get into either a low-voltage or high-voltage situation because if it does, the unit will fail. I am fortunate that I have reliable grid power, but others using this unit as primary power will have pay close attention. I will say, the $1200 cost (roughly 1/5 of say a Sol-Ark 8K), may make this worth the pain for many folks (myself included at least for now).
I am also south of Houston (pearland) and looking at the smaller 3kw growatt. Would love to see your set up, if you're willing. My system would be life support for fridges and a portable AC, seeing that hurricanes love hot summers!
Great thread, I'm learning a lot!
 
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