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Growatt 12kW and Kong 48 Volt Battery

HeikoHabig

New Member
Joined
May 5, 2022
Messages
4
Location
Dallas,Tx
Hello to Everybody.


Let me dive right in.
I purchased a Growatt 12kW 48 V 250 VDC 120 A Off Grid Inverter, i also purchased a Battery 48 Volt Kong 12kWh 233Ah, i did this because we had last year a bad Ice Storm here in Texas where i ended up with no Power for 5 days, pipes froze up and i lost also some animals, anyway not being in that situation again i purchased that setup with also extending to Solar and a Diesel backup Generator down the road.
Anyway i did install the Inverter and wired the AC In @ 220 Volt L1 and L2 and Gnd, then connected the Inverters Battery cables, but also using a resistor prior to charge the Cap before fully connection, i switched on the Inverter and all was looking good, Battery was at a Charge of 15% at this point, the Inverter started to charge the Battery at a rate of 30 Amps, all looked good, i spent about 25 minutes just watching the system get charged, i left to run some arrans and when i came back the system was off, all of it, i could not restart the system, i made sure the AC In was good, which i measured , the battery voltage on the inverter connection read 52 Volts, but still no sign of life, i contacted Support at Signature Solar, where i purchased the Inverter, it took them 2 days to email me back and telling me the Inverter will not start up if i have less than 60 Volt DC on the Battery, that's now where my confusion kicked in, cause it was charging for about 4 hours without error messages or issues, anyway i purchased a 48 Volt Lifepo charger and charged the Battery without the Inverter, she shows full charge now but reads only 53.95 Volts at 100% SOC. Now when i look at the overview of the cells individual, there is a huge imbalance , anyone any idea how to balance them back? Is there a hidden feature on the Kongs where one could access a Balance procedure? I have to say that im very disappointed in regards of the available Documentation for Growatt and BB, i built Industrial Controls for machines and this is something i don't like when there is so little info available.

I also have a COV code sitting now from the BMS , which i believe comes from one cell that is to high.
I will attach some pictures for reference.

Thanks everybody.



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Hello to Everybody.


Let me dive right in.
I purchased a Growatt 12kW 48 V 250 VDC 120 A Off Grid Inverter, i also purchased a Battery 48 Volt Kong 12kWh 233Ah, i did this because we had last year a bad Ice Storm here in Texas where i ended up with no Power for 5 days, pipes froze up and i lost also some animals, anyway not being in that situation again i purchased that setup with also extending to Solar and a Diesel backup Generator down the road.

Count on the generator. The inverter isn't going to do you a lot of good.

That unit BURNS almost 200W full time - even if you have no loads. That's 4.8kWh/day just to have AC power available even if unused. That's 40% of your total battery capacity... just to have the unit on.

Anyway i did install the Inverter and wired the AC In @ 220 Volt L1 and L2 and Gnd,

What did you do with the Neutral?

then connected the Inverters Battery cables, but also using a resistor prior to charge the Cap before fully connection,

Good.

i switched on the Inverter and all was looking good, Battery was at a Charge of 15% at this point, the Inverter started to charge the Battery at a rate of 30 Amps, all looked good, i spent about 25 minutes just watching the system get charged, i left to run some arrans and when i came back the system was off, all of it, i could not restart the system, i made sure the AC In was good, which i measured , the battery voltage on the inverter connection read 52 Volts, but still no sign of life, i contacted Support at Signature Solar, where i purchased the Inverter, it took them 2 days to email me back and telling me the Inverter will not start up if i have less than 60 Volt DC on the Battery,

That makes no sense @SignatureSolarUS

that's now where my confusion kicked in, cause it was charging for about 4 hours without error messages or issues, anyway i purchased a 48 Volt Lifepo charger and charged the Battery without the Inverter,

Did you get the CORRECT "48V LFP" charger. True 48V is 15 cells, so some chargers only charge to 54.75V instead of 58.4V.

she shows full charge now but reads only 53.95 Volts at 100% SOC.

The COV is likely preventing charging to higher voltages.

Now when i look at the overview of the cells individual, there is a huge imbalance , anyone any idea how to balance them back?

The BMS should balance VERY slowly during charging. It typically takes 24 hours to bleed off 1Ah from a cell assuming you can continue to charge it for 24 hours... which it likely won't.

You should probably discharge it for an hour or so and then charge it to full again. Hopefully, you can get to progressively higher voltages over the course of several days/weeks.

Is there a hidden feature on the Kongs where one could access a Balance procedure? I have to say that im very disappointed in regards of the available Documentation for Growatt and BB, i built Industrial Controls for machines and this is something i don't like when there is so little info available.

IMHO, BB is pretty much crap. They just buy the cheapest cells they can get and slap 'em together. Imbalance is a very common problem.

I also have a COV code sitting now from the BMS , which i believe comes from one cell that is to high.
I will attach some pictures for reference.

Disturbing the BMS is reporting voltages in 0.1V increments.
 
Count on the generator. The inverter isn't going to do you a lot of good.

That unit BURNS almost 200W full time - even if you have no loads. That's 4.8kWh/day just to have AC power available even if unused. That's 40% of your total battery capacity... just to have the unit on.



What did you do with the Neutral?

Neutral is not connected, this unit has L1 and L2 connection that comes to the 220 VAC, the Ground is connected, so with the American System that is kinda the Neutral cause the Ground and the Neutral is bonded, that will get you the 120Volt

Good.



That makes no sense @SignatureSolarUS



Did you get the CORRECT "48V LFP" charger. True 48V is 15 cells, so some chargers only charge to 54.75V instead of 58.4V.
i think you are correct on that one, it does say 48volt but the charge is probably not high enough


The COV is likely preventing charging to higher voltages.
any idea to reset that Fault?


The BMS should balance VERY slowly during charging. It typically takes 24 hours to bleed off 1Ah from a cell assuming you can continue to charge it for 24 hours... which it likely won't.

You should probably discharge it for an hour or so and then charge it to full again. Hopefully, you can get to progressively higher voltages over the course of several days/weeks.

will try that

IMHO, BB is pretty much crap. They just buy the cheapest cells they can get and slap 'em together. Imbalance is a very common problem.



Disturbing the BMS is reporting voltages in 0.1V increments.
 
160W is not almost 200W. It uses 9W with no load in Standby.

You quoting specs or actual? Growatt/MPP Solar consistently UNDERreport their idle cunsumption.

Standby is worthless in almost all cases unless the user truly needs 0W of load, and the devices that may cycle on or off don't need AC power to cycle.
 
@HeikoHabig

when you quote partials, please enter a blank line so it becomes quotable to whoever you're responding to. Your responses are intermixed with mine, and I have to copy/paste:

Neutral is not connected, this unit has L1 and L2 connection that comes to the 220 VAC, the Ground is connected, so with the American System that is kinda the Neutral cause the Ground and the Neutral is bonded, that will get you the 120Volt

This is absolutely, positively not the right way to do it. You NEVER use the ground conductor to pass current on the 120VAC legs. Never. You have literally created a shock hazard that may kill someone. I recommend you consult with a licensed electrician. If this unit does not have a neutral, you have the wrong unit.

i think you are correct on that one, it does say 48volt but the charge is probably not high enough

You should be able to get the charger specs from somewhere. Either from where you bought it, the docs or somewhere on the charger itself.

The COV is likely preventing charging to higher voltages.
any idea to reset that Fault?

Yes. You can't. the BMS is protecting the cells that are at peak voltage. Continued charging will destroy those cells.
 
You quoting specs or actual? Growatt/MPP Solar consistently UNDERreport their idle cunsumption.

Standby is worthless in almost all cases unless the user truly needs 0W of load, and the devices that may cycle on or off don't need AC power to cycle.
Starting at 00:10:50

 
So it only takes up 32% of his battery capacity instead of 40%. Not really worth celebrating.

Power saver on this unit is exceptionally useless - 500W minimum load to bring it out of power saver.
 
This is what the Growatt manual states. How would you wire it? 1651864261162.png
Neutral is not connected, this unit has L1 and L2 connection that comes to the 220 VAC, the Ground is connected, so with the American System that is kinda the Neutral cause the Ground and the Neutral is bonded, that will get you the 120Volt

This is absolutely, positively not the right way to do it. You NEVER use the ground conductor to pass current on the 120VAC legs. Never. You have literally created a shock hazard that may kill someone. I recommend you consult with a licensed electrician. If this unit does not have a neutral, you have the wrong unit.
 
Right. and neither option is what you want. The top one is Single phase with 240V output, but you don't want than, and the bottom one is single phase with 120V output.

Don't you want 120/240VAC split phase?
Of course 240split phase. So, do you wire it like watts24/7 suggests carrying neutral from the main panel>growatt>sub panel and does growatt support this?
 
Of course 240split phase. So, do you wire it like watts24/7 suggests carrying neutral from the main panel>growatt>sub panel

Yep.

and does growatt support this?

Growatt didn't even provide you with wiring instructions for 120/240VAC split phase output. I'd trust Ian (watts247). If you got it from him, I would encourage you to reach out to him for support.
 
Yep.



Growatt didn't even provide you with wiring instructions for 120/240VAC split phase output. I'd trust Ian (watts247). If you got it from him, I would encourage you to reach out to him for support.
If neutral is not carried back to the mains panel and only the neutral from the inverter's transformer is used to feed the sub panel, will the GW's transformer still try to balance the utility's street transformer?
 
@HeikoHabig

when you quote partials, please enter a blank line so it becomes quotable to whoever you're responding to. Your responses are intermixed with mine, and I have to copy/paste:

Neutral is not connected, this unit has L1 and L2 connection that comes to the 220 VAC, the Ground is connected, so with the American System that is kinda the Neutral cause the Ground and the Neutral is bonded, that will get you the 120Volt

This is absolutely, positively not the right way to do it. You NEVER use the ground conductor to pass current on the 120VAC legs. Never. You have literally created a shock hazard that may kill someone. I recommend you consult with a licensed electrician. If this unit does not have a neutral, you have the wrong unit.

i think you are correct on that one, it does say 48volt but the charge is probably not high enough

You should be able to get the charger specs from somewhere. Either from where you bought it, the docs or somewhere on the charger itself.

The COV is likely preventing charging to higher voltages.
any idea to reset that Fault?

Yes. You can't. the BMS is protecting the cells that are at peak voltage. Continued charging will destroy those cells.
This is what the Growatt manual states. How would you wire it? View attachment 93706
This is what the Growatt manual states. How would you wire it? View attachment 93706
sunshine_eggo said:
Neutral is not connected, this unit has L1 and L2 connection that comes to the 220 VAC, the Ground is connected, so with the American System that is kinda the Neutral cause the Ground and the Neutral is bonded, that will get you the 120Volt

This is absolutely, positively not the right way to do it. You NEVER use the ground conductor to pass current on the 120VAC legs. Never. You have literally created a shock hazard that may kill someone. I recommend you consult with a licensed electrician. If this unit does not have a neutral, you have the wrong unit.


@sunshine_eggo

Your Statement makes no sense---


The Inverter creates the Neutral internal and produces it on the output side, this Inverter has a Transformer built in that creates the 120Volt , anyway, stating that i created a Shock hazard by connecting the Ground on the Ground makes no sense, you have to have the Ground connected to NOT create a Shock hazard, because the Neutral and the Ground are actually used to return the power run off to the grid, that is actually what makes it safe to touch, besides, what you probably tried to say is that one should not connect L1 and Ground only on a load, without using the Neutral Leg, that is a true statement but that is not what i have done.
 
I have no idea. Good question for Ian.
Several of us have been pondering the issue of ground/neutral/balancing the loads on the utility's transformer with a Growatt low freq AIO, the manufacturer's recommended way of connection, possible electrical safety hazards, and even what internal safety measures GW put into place to prevent their transformer from creating a fire hazard. eggo, I @ you on the thread.
 
Several of us have been pondering the issue of ground/neutral/balancing the loads on the utility's transformer with a Growatt low freq AIO, the manufacturer's recommended way of connection, possible electrical safety hazards, and even what internal safety measures GW put into place to prevent their transformer from creating a fire hazard. eggo, I @ you on the thread.
So, i have following conclusion to what happened to the Growatt Inverter.
The 4 hour or so of charging the Battery (BB - Kong) worked fine, until--- The Battery started to Disconnect (High Temp/COV) and reconnect the Inverter (internal from BMS of Battery), that was not taking to great from the Inverter, this probably damaged the Capacitors, i did had some reconnect sparks inside the Inverter when the battery reconnected (Cycled) to the inverter, i could hear the Contractor in the battery switching, and did see the DSG going on and off on the battery display, @ Eggo, i did connect the Inverter the proper way, regardless of your opinion about that, the Growatt Inverter will completely shut off when there is no DC in , regardless of the AC in, this is in my opinion a really big problem, this could be solved very easy on the software side, the topic about the quality of the BB - Kong is another topic, i spent about a week now on this unit and battery to come to an conclusion and i decide to take the hit of the cost of the Growatt unit and went back to Victron Energy System, at least i have ALL the needed Information and Support available for a proper safe system, there is just to much of a Black Box stuff happening in the Growatt that there is no to little Information available from Growatt, which by the way is very typical for products that are produced in China and sold all over the world, like the poor Schematics that confused you Eggo to how the connections work ( Missing N), at least the Victron units have Full control over the ground inside their units with an active grounding relay, If needed. Honestly, it is to much of an risk for me to use a system like the Growatt inside my building, this is NOT a Safe product to use (In my Opinion).

If one follows procedure that was provided by OEM and then a system is able to destroy itself, that is a big No No , no matter what the system is consist of
 
Several of us have been pondering the issue of ground/neutral/balancing the loads on the utility's transformer with a Growatt low freq AIO, the manufacturer's recommended way of connection, possible electrical safety hazards, and even what internal safety measures GW put into place to prevent their transformer from creating a fire hazard. eggo, I @ you on the thread.
The utility transformer has its own grounded neutral point, the L1 and L2 feeds the primary of the Growatt transformer without carrying the neutral through, the secondary of the Growatt transformer has its own neutral point which is grounded as well. This is perfectly normal and safe in the electrical world.
 
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