Any idea on what happened?

[Jonathan3900]

Hello:

I appreciate any help on this.

I have a Growatt 6k inverter with (2) Big Battery Husky Batteries. I also have 8-350 panels on the roof.

The cabin is in Ohio, so we don't get much sun in the winter.

With all that said, my system was working perfectly, and all of a sudden, a massive spike in power caused the batteries to declare that they were dead and were below the 20% cut-off.

Any ideas on why this would happen? Screenshots added.

Thanks for any advice.

Jonathan

 

[Quattrohead]

So is it back up and running now or has the whole thing died? Looks to me like maybe something shorted out but if it's up and running again then it could have been a data cock up.

 

[Jonathan3900]

So is it back up and running now or has the whole thing died? Looks to me like maybe something shorted out but if it's up and running again then it could have been a data cock up.

It's back up and running and is charging the batteries back up. (I am not at the cabin, so I can only see what the web interface is showing). Its concerning that something could have just wiped all of the power out of the batteries in seconds.

 

[42OhmsPA]

What is at the cabin that could consume that amount of power?
It's interesting the spike is the same time PV is peaking.
Any pumps, compressors or heaters that could have kicked on?

 

[Jonathan3900]

What is at the cabin that could consume that amount of power?
It's interesting the spike is the same time PV is peaking.
Any pumps, compressors or heaters that could have kicked on?

Thanks for the reply. There isn't anything connected other than random lights, battery chargers, etc. I have everything off. That's the crazy part. I have no idea what could cause this. And you are correct; it's weird that it happened right when the PV peaked. So confusing.

 

[OffGridInTheCity]

Assuming there's a BMS - could this have protected the batteries (e.g. caused them to 'go dead') from the spike and then after the spike passed, came back alive and allowed charge/discharge to resume. If so, then perhaps the charge controller caused the huge spike and has now settled down. So the key issue might be an unstable charge controller or one that has a quirk under certain conditions?

**I observe in my own PV array that certain short lived conditions can cause my PV array to spike at 100% (or a bit more) power momentarily. Usually certain sun/cloud combinations. Maybe this kind of thing exceeded the specs of the charge controller?

(Just thinking out load - sorry)

 

[Jonathan3900]

Assuming there's a BMS - could this have protected the batteries (e.g. caused them to 'go dead') from the spike and then after the spike passed, came back alive and allowed charge/discharge to resume?
If so, then perhaps the charge controller allows a huge spike? and has now settled down? So the key question might be a charge controller issue?
(Just thinking out load - sorry)

Thanks for the reply.

I am new to this, so bear with me.

I think the batteries have a BMS in them. Not sure. Regarding the charge controller, I think it's built into the inverter. This is the link to the one we have.

Growatt SPF 6000T DVM Split Phase ,48V 6KW,Solar Inverter 120V 240V 80A MPPT -

Low frequency-inverter 120/240Vac Split Phase output. Integrated MPPT charge controller Optional WIFI/ GPRS remote monitoring. Built-in pure copper low frequency transformer Configurable grid or solar input priority

www.growatt-inverter.com

It seems to be working ok now, but it will take a while to get back to full again. So frustrating.

 

[42OhmsPA]

I'm also curious why the solar production isn't more spread out. One big peak over a short time, you should be seeing a few hundred watts shortly after sun up with your size array.
Is there a fridge or anything with a motor connected that stops and starts?
Do you have other graphs that show current, load etc?

 

[LakeHouse]

It has to be a data error of some sort. I’m guessing you don’t have 9,000 kWh of battery capacity, so there isn’t anywhere that amount of energy could have come from except maybe a lightning strike, and that certainly would have (at least) brought down the entire system.
My best guess would be some sort of surge on a measurement device (e.g., a few Volt spike across a shunt circuit could get interpreted as many thousands of amps flowing). As to the cause, not really enough info to pin one down.
The strange battery SOC report sort of makes sense; the system is just as confused by all this as we are and is just making a guess as to where the batteries are, possibly based on voltage, which isn’t a very reliable indicator for LFP batteries. Is the battery voltage showing normal? Any change before and after the event?

 

[Jonathan3900]

I'm also curious why the solar production isn't more spread out. One big peak over a short time, you should be seeing a few hundred watts shortly after sun up with your size array.
Is there a fridge or anything with a motor connected that stops and starts?
Do you have other graphs that show current, load etc?

I think the reason why is shows one big spike is that the graph is minimal. The panels created power all throughout the day until this big spike.

I do have a fridge (small one), and it spikes on every hour or two. 70-80 watts.

I attached a graph of today. (please note that when it says the batteries are at 100%, they aren't. Growatts monitoring system thinks at 52 volts, they are full).

 

[Jonathan3900]

It has to be a data error of some sort. I’m guessing you don’t have 9,000 kWh of battery capacity, so there isn’t anywhere that amount of energy could have come from except maybe a lightning strike, and that certainly would have (at least) brought down the entire system.
My best guess would be some sort of surge on a measurement device (e.g., a few Volt spike across a shunt circuit could get interpreted as many thousands of amps flowing). As to the cause, not really enough info to pin one down.
The strange battery SOC report sort of makes sense; the system is just as confused by all this as we are and is just making a guess as to where the batteries are, possibly based on voltage, which isn’t a very reliable indicator for LFP batteries. Is the battery voltage showing normal? Any change before and after the event?

Hello:

Actually, I do have 10.5kWh of battery capacity.

I am not there, but as far as I can tell, they are charging back up.

My electrician is thinking the inverter is junk. Not sure if he's on to something.

What makes me question everything is what could have possibly taken full batteries and taken all of the power out of them in a minute. Very confusing.

 

[LakeHouse]

Hello:

Actually, I do have 10.5kWh of battery capacity.

I am not there, but as far as I can tell, they are charging back up.

My electrician is thinking the inverter is junk. Not sure if he's on to something.

What makes me question everything is what could have possibly taken full batteries and taken all of the power out of them in a minute. Very confusing.

Right, 10.5kWh of capacity, but the graph shows over 9000 kWh. That’s not a Wh/kWh typing error. The data shows 1000x your battery capacity. Your batteries certainly couldn’t have done that.
The reason I ask about the voltage is to answer the question of whether or not you batteries actually DID discharge, or is your monitor just confused by some strange data. If battery voltage before and after we’re more or less the same, it’s possible nothing actually happened.
On the other hand, if voltage was notably lower afterwards, likely some energy did go somewhere.

 

[MisterSandals]

Looking at this differently (and only did skim reading, sorry), wondering about the solar array.

You have 8x 350W panels. What is the panel Voc and how are they arranged?
I researched from link max input voltage is 150V and MPPT range is 60V-145V.

Seems possible a passing cloud could create a voltage anomaly and if array voltage close to max, results in undefined behavior?

 

[42OhmsPA]

I think the reason why is shows one big spike is that the graph is minimal. The panels created power all throughout the day until this big spike.

I do have a fridge (small one), and it spikes on every hour or two. 70-80 watts.

I attached a graph of today. (please note that when it says the batteries are at 100%, they aren't. Growatts monitoring system thinks at 52 volts, they are full).

That graph looks much better, what's yesterday's look like?
Yea, battery estimates with Lifepo4 aren't good unless you have comms with BMS.

 

[Jonathan3900]

Right, 10.5kWh of capacity, but the graph shows over 9000 kWh. That’s not a Wh/kWh typing error. The data shows 1000x your battery capacity. Your batteries certainly couldn’t have done that.
The reason I ask about the voltage is to answer the question of whether or not you batteries actually DID discharge, or is your monitor just confused by some strange data. If battery voltage before and after we’re more or less the same, it’s possible nothing actually happened.
On the other hand, if voltage was notably lower afterwards, likely some energy did go somewhere.

Ok. I get ya. Well, our alarm system did go out until this morning. So they did go dead (less than 20%). Maybe (as one of the responses said) it was a short. I would have figured a fuse would have blown if that was the case. Ugh.

 

[Jonathan3900]

Well, it happened again. Same huge spike. Batteries this time went down to 75% instead of dead. Is there any way to reset a Growatt inverter and see if that clears it up?

 

[42OhmsPA]

Do your batteries have a heater that could be turning on?
Still that's a massive spike, over 25a @ 240v.
Only other thought is compressor on fridge is locking up but that should be tripping a breaker.
I'm at a loss.
There should be a reboot somewhere in the menu.
Any outdoor 240v receptacles? Maybe someone is charging up ?
Can you see a chart for battery current when it happens?

 

[Jonathan3900]

Do your batteries have a heater that could be turning on?
Still that's a massive spike, over 25a @ 240v.
Only other thought is compressor on fridge is locking up but that should be tripping a breaker.
I'm at a loss.
There should be a reboot somewhere in the menu.
Any outdoor 240v receptacles? Maybe someone is charging up ?
Can you see a chart for battery current when it happens?

Thanks for the reply. There isnt a heater on them now. I turned it off since it's staying above freezing. .

I never thought about the fridge. Hmmm. Got me thinking. Wonder if it's having issues.

I've looked at the menu, and from what I can tell, there isn't. I need to research this more.

No 240 receptacles. We also have cameras, so I know no one is trying to "use" my electricity.

Not sure I can get that deep into the monitoring software to see the battery current. I attached a pic to this about the discharge for the past week. Not sure that helps.

 

[BenQ]

Well, it happened again. Same huge spike. Batteries this time went down to 75% instead of dead. Is there any way to reset a Growatt inverter and see if that clears it up?

Do these screenshots say that you’re exporting to grid? Either way, I believe the comments above are correct that you have either 1. an electrical device that is shorting out or 2. a busted growatt system. Being remote you won’t know till you get on site. When you do get on site consider adding a Smart shunt to your system so you can better monitor situations like these remotely.

 

[Jonathan3900]

Do these screenshots say that you’re exporting to grid? Either way, I believe the comments above are correct that you have either 1. an electrical device that is shorting out or 2. a busted growatt system. Being remote you won’t know till you get on site. When you do get on site consider adding a Smart shunt to your system so you can better monitor situations like these remotely.

Thanks for your reply.

We arent exporting any to the grid.

Do you have any recommendations of a Smart Shunt? I have been looking.

 

[42OhmsPA]

Looking for reliable battery monitor suggestions

I have a 16s 48V pack made with EVE 105ah cells and I am having a hard time finding a monitor that is fairly accurate. I have tried a few but not making much progress. In the latest example, the pack is fully charged and at rest. The voltage reading is fairly good given that it’s only I...

diysolarforum.com

 

[OffGridInTheCity]

To the theory the GroWatt is having internal 'control' issues. I've been running a pair of AIMS 12,000w inverters for several years. One of them - at 25,000hr (4 yrs, last Dec) suddenly starting exhibiting voltage drops every 30sec after the load got higher than 5%. Just for 'no reason' that I can tell. The thought from AIMS support is that the control board (somehow) is not working properly anymore.

All I can say to my AIMS situation is YIKES!!! No way for me to diagnose at an intermittent 'control board' failure.

I don't say this to be discouraging - just sharing that it's possible the electronics can start showing hiccups. If all else fails, do you have a backup/replacement unit you can try?

 

[Jonathan3900]

To the theory the GroWatt is having internal 'control' issues. I've been running a pair of AIMS 12,000w inverters for several years. One of them - at 25,000hr (4 yrs, last Dec) suddenly starting exhibiting voltage drops every 30sec after the load got higher than 5%. Just for 'no reason' that I can tell. The thought from AIMS support is that the control board (somehow) is not working properly anymore.

All I can say to my AIMS situation is YIKES!!! No way for me to diagnose at an intermittent 'control board' failure.

I don't say this to be discouraging - just sharing that it's possible the electronics can start showing hiccups. If all else fails, do you have a backup/replacement unit you can try?

Interesting...

My electrician does not like Growatt. Not sure if there is another better option. I hate to throw away money and get something new, but it needs to work. I contacted Growatt and they haven't said a thing. Their customer service is HORRIBLE.

I think what I am going to do it to get a different monitoring device (suggestions welcome), and go down and shut off the fridge for a week or so. Maybe that would shed insight on this mess.

 

[42OhmsPA]

I think what I am going to do it to get a different monitoring device (suggestions welcome), and go down and shut off the fridge for a week or so. Maybe that would shed insight on this mess.

Solar assistant. io
Almost certain growatt is supported.

 

[Jonathan3900]

Solar assistant. io
Almost certain growatt is supported.

Thank you for your help. I hope to get this thing resolved!!!