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Questions About Growatt SPF 3000TL LVM-ES 3KW

Sunshine22

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Jan 27, 2022
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I've been reading this forum regarding the Growatt issue of stopping solar after the battery has reached full charge. I have a couple questions. Below is what I'm using:
SPF 3000TL LVM-ES 3KW
USE2
Bulk 57.5V #19
Float 55V #20
DC Cutoff 46V #21
Batteries - 4 x Zooms 12.8v 200ah LiFePO4 in series
No Utility
4000 watts solar
Priority is set to SOL

I have not connected the inverter to a computer, so my questions and observations are based on the Growatt's display. What program do you guys recommend to monitor the details?

Scenario: The "Charge" light is solid (no charging) and the battery is at 54.8 volts or so with no load. During daylight hours I can run a 300 watt load all day. The display will show the "solar" icon with slightly more watts coming in than going out.
1) Does this mean the load is purely carried by solar?
2) If I hit the inverter with a large load such as a shop vac 1200 - 1500 watts. The inverter "charge" light begins blinking and the fans ramp up. The "solar" will show around 2300 watts with 1200 - 1500 watts going out. Even if the vac is only on a minute or 2 the charging will continue at around 1200 watts for 1/2 hour until it tops up the battery. At that point the "charge" light will stop blinking, and the fans ramp down. Since the solar appears to be pulling in more than enough to power the load, why does the Growatt go into bulk charge? Shouldn't the load have been purely on solar?
3) With no load - after the "charge" light quits blinking the display will still show the solar icon with anywhere from 50 - 100 watts coming in. Is that just to maintain the unit, or is it actually still powering the battery - even though the "charge" light is solid?
4) If the inverter display is showing the "solar" icon with current coming in does that mean that it is indeed using solar, or do I need a computer program to see the details?

If the Growatt's "solar" icon showing connection and current means it is still using solar to power the load, it would appear my unit is not having the problem of cutting off solar after the battery is fully charged. I purchased the unit from Ian in February 2022, so did something change (for the better) recently?

Thank you for your help!
 
Sounds like you have a real nice system. Let me take a stab at your reported results.

1. Sounds like it. You will always have efficiency loss from source to load. It takes more power in than you will get out. But your array is big enough to cover that plus the load so your battery does not get called upon.
2. Starting a large load likely draws enough current so it exceeds your wattage of your solar array if even for a short time. The battery has to supply at this point. How the Growatt handles the change over and back (solar supplied/battery supplied) could be the reason it takes 1/2 hour to get the battery back up to full.
3. Your system will have a constant load from the Growatt AIO even if there is no other load. 50- 100 watts sounds about what I have read is idle loading.
4. This would take someone familiar with the Growatt unit so I have no answer.
 
Some inverters do not account for the total power consumed, but only measure the apparent power. This is related to what is called "power factor" and is an important component to be factored in with anything running an electric motor, and also some other appliances.

I'd say the watts coming into the controller is a more accurate measure of the total power then the inverter output number. You can verify this with a clamp meter measuring the total draw of the vac.

BTW, if you get a clamp meter that can measure "inrush current", you can quantify what Matt is mentioning in section #2 of his response. The "inrush" clamp with measure the starting surge, which is the current drawn for the first 500 milliseconds or so immediately upon startup. I use an UniT216C.

So, what's happening is that the inverter reading only the apparent power is giving you a lower reading then the total draw, which in part is coming from your batteries, which get drained while the vac is running. After the vac get's shut off, the inverter is now trying to get the batteries back up to full-charge, which is taking about 30 minutes or so.
 
I've been reading this forum regarding the Growatt issue of stopping solar after the battery has reached full charge. I have a couple questions. Below is what I'm using:
SPF 3000TL LVM-ES 3KW
USE2
Bulk 57.5V #19
Float 55V #20
DC Cutoff 46V #21
Batteries - 4 x Zooms 12.8v 200ah LiFePO4 in series
No Utility
4000 watts solar
Priority is set to SOL

I have not connected the inverter to a computer, so my questions and observations are based on the Growatt's display. What program do you guys recommend to monitor the details?

Scenario: The "Charge" light is solid (no charging) and the battery is at 54.8 volts or so with no load. During daylight hours I can run a 300 watt load all day. The display will show the "solar" icon with slightly more watts coming in than going out.
1) Does this mean the load is purely carried by solar?
2) If I hit the inverter with a large load such as a shop vac 1200 - 1500 watts. The inverter "charge" light begins blinking and the fans ramp up. The "solar" will show around 2300 watts with 1200 - 1500 watts going out. Even if the vac is only on a minute or 2 the charging will continue at around 1200 watts for 1/2 hour until it tops up the battery. At that point the "charge" light will stop blinking, and the fans ramp down. Since the solar appears to be pulling in more than enough to power the load, why does the Growatt go into bulk charge? Shouldn't the load have been purely on solar?
3) With no load - after the "charge" light quits blinking the display will still show the solar icon with anywhere from 50 - 100 watts coming in. Is that just to maintain the unit, or is it actually still powering the battery - even though the "charge" light is solid?
4) If the inverter display is showing the "solar" icon with current coming in does that mean that it is indeed using solar, or do I need a computer program to see the details?

If the Growatt's "solar" icon showing connection and current means it is still using solar to power the load, it would appear my unit is not having the problem of cutting off solar after the battery is fully charged. I purchased the unit from Ian in February 2022, so did something change (for the better) recently?

Thank you for your help!

 
I'm not a Solar/Growatt guru yet! But your system seems to be working as "designed" When the panels Icon is showing, solar is on, input into the inverter depends on many factors, number of panels, rating, losses, battery SOC....etc. LiPo4 batteries as many other chemical based batteries charges up kind of slow, it takes time for those critters in there to get it together. The greater the load the more time it will take for the battery to replenish that energy, it takes a lot of amperage for panels to supply a meaningful load, my shop vac inrush is around 21 amps, the wire gauge on the panels is not big enough (assuming 10AWG) pure copper, I know the charts say it can but.... to take a big load without losses, and dropping the voltage, the inverter will also detect the surge and is going to determine a course of action, so the batteries have to jump in and assist, so IMHO the inverter is doing what is supposed to. I hope that clears things up for you or at least give you some assurance that your system is working great! If all else is tight and secured, then I say you got a good system. I know Growatt still has some improvements to do but slowly but surely this product is looking better by the day, I cleaned up one of my backup systems, it's and older system with LiOn batteries, and it works great, but is messy, wires everywhere, and I do take pride on my wire jobs! But there is no way around it you got to have wires to connect things up to each other! With the Growatt is so much simpler and much, much cleaner looking! Now if I could connect the batteries wireless ly, that would be perfect! i like to add a detail I forgot to mention, check out Will's video on the Battery-less Growatt it might help on trying to understand why batteries have to kick in even if you have enough solar power coming in. The test he did shows that even if you have enough solar your batteries will have to be present in the system to cover any surge that the solar circuit can't handle. Please correct me if I'm wrong but it is what I was able to gather from his test.
 
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So, I put a ticket to SS in reference to the Growatt 3K 48v not switching to batteries, batteries SOC is at 7% IAW the Smart Shunt, and each individual battery voltage, since the Growatt don't have a built-in shunt, it can't determine the state of charge unless you own the server type battery packs with communications. So, this morning I powered up the Growatt as I do in the mornings and it won't change to batteries, nothing has changed from last night when I turn the power off as I do at night, since I use this Growatt with a mini split unit upstairs to equalize the temperature. The battery voltages indicate the correct SOC and matches what the Smart Shunt reads. The bank's voltage matches what the Smart shunt and the Growatt reads. I have it setup to use batteries and charge from solar as priority, but still this morning it insists and goes into grid bypass mode, which I don't want, I want the batteries to be depleted down to the low voltage disconnect set in the Growatt settings and is IAW the manufacturers specs. After they are depleted to that point, I check voltages to see if there are any drifters so far, they discharge just about right, then I do a full charge, rinse and repeat, this is the first time I have encountered this issue, as I said before nothing has changed except the batteries SOC. The mini split unit is an inverter type and it starts slow then it ramps up according to the set temperature. then it hovers around 250W with ramp ups to 500W as needed so, the amperage draw is low. What could be the issue? I have re-booted the Growatt several times with the same results. It always starts drawing from the grid even though there is 7% charge on the batteries. At the moment even though it says is on the grid bypass mode the Smart Shunt says the batteries are being drawn .66A and 34W but I think that's from the Shunt itself. There is a picture that shows the battery usage for the last 5 days without any issues. I have attached some pics to show what I’m dealing with. Thanks.
 

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Since you are down to 7% charge on your battery it is possible that any large load drops the voltage down below the "Battery power to utility setpoint" voltage. What is that set at?
 
Since you are down to 7% charge on your battery it is possible that any large load drops the voltage down below the "Battery power to utility setpoint" voltage. What is that set at?
Hello, thanks for the reply... can you point me to that setting? Is it in the Growatt's settings? The AC unit is an inverter type so is very efficient but the issue is that the Growatt is not drawing from the batteries as setup in the settings, normally the Growatt will disconnect once the Low voltage setting is reach which for these batteries is 46.4v and is setup IWA manufacturers and normally it does but this time the voltage still at over 50v, so it should at least go into battery mode, unless something changed w/o me knowing about overnight. On the phone's Smart Shunt picture you can see that the SOC was 7% with only 188AH drawn, it's a 200ah bank I mean is close enough but something is out of wack.
 
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Should be as well as the "Utility power to battery setpoint" which says the battery has enough voltage (SOC) to transfer out of utility. Depending on if your batteries communicate or not it might be setting 12,13,21 for voltage or SOC
 
Should be as well as the "Utility power to battery setpoint" which says the battery has enough voltage (SOC) to transfer out of utility. Depending on if your batteries communicate or not it might be setting 12,13,21 for voltage or SOC
Hello, thanks for the reply, I forgot to mention that the batteries are just regular dumb batteries, 12v 100ah Chins not the smart type.
 
Incidentally voltage for the battery could come back up some after the load is transferred to the utility. Battery voltage under load is not the same as resting. Indeed your unit might have some low level charging occurring to the battery even though utility charging is tuned off.

My AIO is set for a battery to utility at 25.4v (equivalent to 50.8 for a 48v inverter). It transfers early morning to utility and by my wakeup time the battery is reading 25.6v to as high a 26.0v by the time I look at it.
 
Hello, thanks for the reply, I forgot to mention that the batteries are just regular dumb batteries, 12v 100ah Chins not the smart type.
So here is an update, I went ahead and charged them up for a few minutes with solar, just to see if I could trigger a mode switch and it worked, the mini split is working now and is drawing from the batteries. The Growatt server webpage reflects that and the smart shunt shows the voltage and amps draw correctly, seems like the Growatt is slow on switching from mode to mode, I guess it has to do a series of checks before it can switch modes and sometimes it has to wait for those checks to pass or fail before doing so and sometimes it just goes into a default mode pending other actions to take place. I don't see why it would not go to battery mode since overnight the voltage tends to go up and settles.
 
Incidentally voltage for the battery could come back up some after the load is transferred to the utility. Battery voltage under load is not the same as resting. Indeed your unit might have some low level charging occurring to the battery even though utility charging is tuned off.

My AIO is set for a battery to utility at 25.4v (equivalent to 50.8 for a 48v inverter). It transfers early morning to utility and by my wakeup time the battery is reading 25.6v to as high a 26.0v by the time I look at it.
Which batteries are you using? Server type? I think these chins are great but lack of communication with the Growatt is going to be challenging to deal with. One of the main reasons I got the Growatt was to make things simpler and it has but yeah the dumb batteries and the Growatt might not work for me. I been looking at the EG4s but people seems to have mix comments about them. I don't want to have any issues with a costly investment like that, for me anyways.
 
Presently using a simple lithium 80ah battery. Nothing fancy.

BTW did you ever find the settings for voltages when it transfers back and forth?
 
Presently using a simple lithium 80ah battery. Nothing fancy.

BTW did you ever find the settings for voltages when it transfers back and forth?
I checked all the settings on the Growatt, I use their web server on WIFI but didn't see anything I'm using the US2 mode since it allows me to set the float voltage (55.2v) separately from the max charging voltage which is 56.8v IAW the manufacturer. Do you know what is this battery to mains working voltage setting, it is at 48v but my under voltage cut off is at 46.4v, not sure if they relate to each other but I'm confused, where is the setting to set the low voltage disconnect, I don't see that specific setting on the Growatt server settings menu under the US2 battery mode.
 
Sorry don't know about their Wifi stuff. You might need to go to the unit. On my EAsun AIO unit the "Battery discharge limit voltage" is a separate setting from the utility and battery transfer voltages. It is really low by default at 20V (for user defined and lithium battery types). I have mine set to 22v I do not want to drive the BMS into low voltage cutout.
 
Sorry don't know about their Wifi stuff. You might need to go to the unit. On my EAsun AIO unit the "Battery discharge limit voltage" is a separate setting from the utility and battery transfer voltages. It is really low by default at 20V (for user defined and lithium battery types). I have mine set to 22v I do not want to drive the BMS into low voltage cutout.
Agree, me neither. all the battery settings are IAW manufacturer specs for these batteries I use. The Growatt is working as is supposed to it is down to 2 percent or 197 WH, going to wait until it shuts down and check each battery for any possible drifting, in the past they are spot on. I'm thinking that because the Growatt don't have a built-in shunt and can't determine SOC on non-smart server type batteries without communications, it has issues with just the voltage reading, even though is exactly the same voltage that the Smart Shunt says and the only way to get the Growatt to switch to battery mode is by forcing a charge condition from the built-in solar charger. Just my wild guess but could be some other setting I need to look at, most of the settings on the US2 mode are still on default, just changed the float voltage, the max charging current, the under-voltage setting, and the priority to use batteries then charge from solar no charging from grid. All to the manufacturer's specs. I did a search on this battery to mains working voltage setting which is set to 48v by default, from what I gather when the batteries reach 48v the Growatt switches to mains mode? The under voltage seems to apply just when there is power surge that goes under that voltage setting.
 
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I was reading through Growatts manuals this weekend for various models and I spotted in the battery selection area a possible reason you lacked settings for Bypass (AC passthrough) voltages. All it will give you is the low voltage cut off if you have selected lithium battery. It disables those because that selection is intended for BMS communication connected setups. Instead you use US2 for "dumb" lithium battery setups. Not sure if this was why you report that you could not find them but I thought it was worth mentioning.
 
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Since you are down to 7% charge on your battery it is possible that any large load drops the voltage down below the "Battery power to utility setpoint" voltage. What is that set at?
Thanks for the reply, so I found that setting you mentioned, and is set for 48v which still well below the current voltage, the inverter don't draw that much amperage like for the voltage to go below the cutoff. Which is 46.4v if I recall that correctly. There is no deep sagging of the voltage at startup either. I suspected the battery(es) and I confirmed that, 2 of the batteries capacity were below the others and they were hitting their disconnect early, since then I got a refund and since I want to go with the server type batteries in the near future I just did a balancing cycle with individual capacity test to establish a good solid reference point and adjusted the cutoff on the AIO inverter, I'm still getting advertised capacity plus, so I'm happy with the outcome.
 
Can anyone comment on how to change the Growatt WIFI data logger server timing, I did it initially when I first got the adapter and everything work fine, the server updates were frequent, not at the setting I used but a lot faster than now. The default preset sets it for 5 minutes intervals, and every time you disconnect the battery bank for maintenance the data logger looses your settings and defaults to it's settings and there are some settings that are not appropriate for LiPo4 batteries, so I just end up doing a browser refresh while logged in to their dashboard, but I really want to be able to change the data logger settings specifically the server timing interval without having to do a factory reset and start all over again. Seems like the data logger should save your settings in permanent memory (rom) but looks like it just store it on (ram) and if the power is lost you loose them. I have attached a snip of the setting I'm talking about. Comments?
 

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