Hello !

Dear friends, it is about two months now since I have installed a small grid assisted solar setup for personal use. My current setup is: 12x Longi 535W bi facial panels, 2x Growatt SPF 5000ES inverters working in parallel, 2x Dyness battery packs with total of 9.6kWh capacity and 1x WiFi communication dongle. Since the beginning I've noticed very erratic behavior when there is no sufficient or no sun power. My current "back to AC" setting (12) is at 25% battery, "back to battery"(13) is at 30% and the ''low DC cut off'' (21) is at 20%. After reaching 25% battery capacity, both of the inverters are indicating that they are in AC bypass mode but the battery slowly( in about 2-3 hrs) continues to discharge to 20% ( even being all the time in AC bypass mode) and than the ghost has two scenarios: 1. Grid AC charge the battery to 30%; 2. the battery continues to discharge to 0%  and the whole system shuts down or grid AC is starting to charge the battery from 0% to whatever percentage the ghost choose (this morning stopped at 54%).

So I am tying to figure out why after reaching 25% there is still battery "leakage" and is this battery or inverter problem, or the communication between them is somehow not OK ? If I have to be honest the fact that sometimes the battery continues to discharge to 0% is bothering me the most.

What have I tried so far:

1. Tried both CAN and RS485 communication with the battery with according jumper setup on the front panel of the master battery (no error 20).

2. Switching places of the inverters (master-slave).

3. Tried the original Dyness (straight) communication cable (works in RS485 mode with protocol 01 in menu 36 and also this cable works in CAN mode with protocol 51 in menu 36) and also made my own cable (1 and 2 pins on inverter and 1 and 3 pins on battery working only in CAN mode with protocol 51 in menu 36).

4. Switching places of the batteries (master-slave).

5. Disconnecting ground from the battery and then from the inverters (just trying).

6. Reset the inverters with 305 code before changing any major setting.

7. Saying many bad words.

Other settings: 01- SBU; 02- 50A; 03-UPS; 04-DIS; 05-Li; 12-25%; 13-30%; 14-OSO; 18-ON; 21-20%; 23-PAL; Firmware: 067 01 1.04, 068 01 1.04

 

I will be really grateful if someone have an idea what might be the problem and how to solve this puzzle !

 

Edited December 13, 20222 yr by zorrotto

@zorrotto Nothing to do with communication, the Growatt 5000 ES has a no-load power consumption of <60 W (see page 38 on your manual), that power is taken from your battery. in your case two in parallel it will drain about 2 Amps from your battery.

 

Thanks for the reply, Antonio !

Yes, I knew that the inverters has empty load power consumption but I had no idea that this load is drawn only from the battery. Nevertheless why sometimes when the SOC drops below 20% the inverter does not recharge the battery with grid AC (as usually does) to the level stated in menu 13 and instead it continues to drain the battery till 0% ?

Is there any functional solution to stop this discharge below 20% ?

 

Edited December 13, 20222 yr by zorrotto

2 minutes ago, zorrotto said:

Thanks for the reply, Antonio !

Yes, I knew that the inverters has empty load power consumption but I had no idea that this load is drawn only from the battery. Nevertheless why sometimes when the SOC drops below 20% the inverter does not recharge the battery with grid AC (as usually does) to the level stated in menu 13 and instead it continues to drain the battery till 0% ?

Is there any functional solution to stop this discharge below 20% ?

 

It's usually a need for top balancing, if you check the battery graph it drops from like 17% to 0%.

This morning when the battery was totally discharged the master inverter was indicating that he is using only the battery and the slave was indicating that it is in AC bypass mode.

11 minutes ago, Buyeye said:

It's usually a need for top balancing, if you check the battery graph it drops from like 17% to 0%.

So, should I do something or this is normal battery balancing ?

6 minutes ago, Buyeye said:

It's usually a need for top balancing, if you check the battery graph it drops from like 17% to 0%.

@Buyeye. That I'm not sure, mine very seldom came down to that level. I've seen it a couple of time and it does take charge from grid, the moment my battery gets to 48 V it charges from grid see dashboard.

If I switch to USE or US2 user defined settings in menu 05 will there be any difference ?

Edited December 13, 20222 yr by zorrotto

5 minutes ago, zorrotto said:

If I switch to USE or US2 user defined settings in menu 05 will be any difference ?

I really don't know, and there has been quite a length discussing in this forum, some are in Favour, others disagree. I run my system on user 2 and I'm very happy with the results, I'm verry conservative with my battery settings, my setting for bulk charge is 55,3 V, OEM recommends 56 V, float to 53,5 OEM recommends 54. sometimes does not reach 100% SOC but it goes to about +_ 95% and once a month I take it to 56 V to balance the cells.

13 hours ago, zorrotto said:

switch to USE or US2

Run a test with USE mode. US2 expects a comms cable between battery and Inverter and acts pretty much the same as Li modes, only difference being you can set the voltages manually but the BMS comms with Inverter continue and the outcome will be similar to what you now have with Li mode.
In USE mode, disconnect the comms cable, set everything manually as per your battery specs. Leave it on USE mode for a day or two and monitor the battery capacities and voltages directly from the battery. The BMS will (should) manage the battery charge by itself. 
 

I am experimenting for more than a month now, so I will definitely try USE and US2 modes. Firstly I will try US2 mode because I don't want to interrupt communication between the battery and the inverter but I will also try the USE mode to see will there be any difference. The most stable and reliable setting wins !

8 minutes ago, zorrotto said:

I am experimenting for more than a month now, so I will definitely try USE and US2 modes. Firstly I will try US2 mode because I don't want to interrupt communication between the battery and the inverter but I will also try the USE mode to see will there be any difference. The most stable and reliable setting wins !

Take note that US2 setting says: (Suitable when using LI battery without BMS communication)

1 hour ago, Antonio de Sa said:

(Suitable when using LI battery without BMS communication)

Thats what the manual says. What they really mean is that if there is no preprogrammed protocol for the specific battery the US2 can be used. If the Li protocol does exist for the battery type, then comms will still take place and will influence the charge parameters.
I have tested it with mine as the Li Protocol exists. If I disconnect the comms, the Inverter shuts down.
The only way to get around it is to use USE mode with no comms cable or to shutdown the Inverter, then disconnect the comms cable and then apply US2 mode after restart. In that case USE and US2 will be identical in operation, i.e. voltage control only.

I apply USE mode for 2 days every so often to get the BMS to recalibrate. Then I revert to the Li protocol until I see that the voltage starts drifting lower and lower again whilst showing full capacity.
53,6V is 100% for my battery. Li Protocol eventually ends up at 52,6V battery voltage still showing 100% and 110Ah. And it decrease ever more. Once I do the voltage charge for a cycle or two, it's back at 53,6V 100%. The Li Protocol algorithms and the BMS are a far cry from consistency. An overrated technology that needs a lot more refinement to be what the marketing claims. At least that's my experience with the Growatt Firmware.
 

Edited December 14, 20222 yr by zsde

16 minutes ago, zsde said:

Thats what the manual says. What they really mean is that if there is no preprogrammed protocol for the specific battery the US2 can be used. If the Li protocol does exist for the battery type, then comms will still take place and will influence the charge parameters.
I have tested it with mine as the Li Protocol exists. If I disconnect the comms, the Inverter shuts down.
The only way to get it around is to use USE mode with no comms cable or to shutdown the Inverter, then disconnect the comms cable and then apply US2 mode after restart. In that case USE and US2 will be identical in operation, i.e. voltage control only.

I apply USE mode for 2 days every so often to get the BMS to recalibrate. Then I revert to the Li protocol until I see that the voltage starts drifting lower and lower again whilst showing full capacity.
53,6V is 100% for my battery. Li Protocol eventually ends up at 52,6V battery voltage still showing 100% and 110Ah. And it decrease ever more. Once I do the voltage charge for a cycle or two, it's back at 53,6V 100%. The Li Protocol algorithms and the BMS are a far cry from consistency. An overrated technology that needs a lot more refinement to be what the marketing claims. At least that's my experience with the Growatt Firmware.
 

Sure, I understand what you are saying, you are 100% correct, the difference between our settings is very simple, I don't have any comms cable connected to my battery, since day one my system has been running on US2.

with the communications the issues will appear. Trust me as soon you switch to LI comms the inverters will not trigger the AC bypass in some modes. Growatt has really big firmware flaws with this. That is also the reason as they are right now telling everyone who reports issues that their batteries are not compatible. The the own ARK modules are suffering of the same issues they are not mentioning... If you are not depending on the SoC of your batteries stick with USE modes...

@zorrottoDid you find any solution to this problem? I have the exact same problem with a Growatt SPF 5000ES and Pylontech LiFePo batteries. At night, when the inverter works on Grid utility power with bypass, the batteries are getting depleted below 20% over the night.

I tried calling Growatt support from UK but they refused to give me any suggestions because they said they dont cover Europe... and I should call Germany Growatt support. Guess what? The Germany support phone number is not valid and you cant contact them.

23 minutes ago, Spiki said:

@zorrottoDid you find any solution to this problem? I have the exact same problem with a Growatt SPF 5000ES and Pylontech LiFePo batteries. At night, when the inverter works on Grid utility power with bypass, the batteries are getting depleted below 20% over the night.

I tried calling Growatt support from UK but they refused to give me any suggestions because they said they dont cover Europe... and I should call Germany Growatt support. Guess what? The Germany support phone number is not valid and you cant contact them.

Growatt 5000 ES when on SUB mode will drain +_ 0.9 Amps from the battery. see page 30 on your manual " No load power consumption " so in theory over 10-hour night should drain from your battery by about 9 amps. If it drains more than that I would think that there is something wrong with the inverter. In my case I have two in parallel, and I can clearly see pulling 1.9 Amps from my battery. see dashboard.

2 hours ago, Antonio de Sa said:

Growatt 5000 ES when on SUB mode will drain +_ 0.9 Amps from the battery. see page 30 on your manual " No load power consumption " so in theory over 10-hour night should drain from your battery by about 9 amps. If it drains more than that I would think that there is something wrong with the inverter. In my case I have two in parallel, and I can clearly see pulling 1.9 Amps from my battery. see dashboard.

Thank you for your reply.

My Inverter is configured in SBU mode, but Im guessing the same rule that you mentioned applies in this mode too, correct? I'm aware of the No load power consumption, but I thought this can also be powered by the 220V AC grid voltage, not only by the batteries. I'm guessing there is no way to make it run from the grid, instead of the batteries, right? Also, have you tried turning on the option for power saving when there is no load? I'm guessing this current goes to 0 in this case?

 

I have 10.5 Kwh batteries. I did not make any precise math for the amps over the night but from my point of view, its depleting more than 10% over 10 hours. Which is 1050 Wh, divided by 48 volts results 21 Amps which is double than the expected current consumption. (I will monitor the current consumption more precisely so I make sure I do not get anything wrong).

Taking the 0.9 Amps per hour, this should mean 9 A for 10 hours, which is 432 Watts (48V * 9A). 432 Watts should only be 4% from my 10.5 Kwh batteries... which is reasonable, but I think mine takes much more.

I`m familiar with Grafana but how did you monitor the instant current consumption?

Thanks in advance for your input!

3 minutes ago, Spiki said:

Thank you for your reply.

My Inverter is configured in SBU mode, but Im guessing the same rule that you mentioned applies in this mode too, correct? I'm aware of the No load power consumption, but I thought this can also be powered by the 220V AC grid voltage, not only by the batteries. I'm guessing there is no way to make it run from the grid, instead of the batteries, right? Also, have you tried turning on the option for power saving when there is no load? I'm guessing this current goes to 0 in this case?

 

I have 10.5 Kwh batteries. I did not make any precise math for the amps over the night but from my point of view, its depleting more than 10% over 10 hours. Which is 1050 Wh, divided by 48 volts results 21 Amps which is double than the expected current consumption. (I will monitor the current consumption more precisely so I make sure I do not get anything wrong).

Taking the 0.9 Amps per hour, this should mean 9 A for 10 hours, which is 432 Watts (48V * 9A). 432 Watts should only be 4% from my 10.5 Kwh batteries... which is reasonable, but I think mine takes much more.

I`m familiar with Grafana but how did you monitor the instant current consumption?

Thanks in advance for your input!

The current value it's pulled out from the battery, so it's quite accurate. My battery has a seplos BMS, all information is retrieved via Modbus protocol, don't ask me how I'm BC before computers, my son done it for me.

here is the info I get from my Battery.

 

 

And this is the info from my two Growatts.

 

Edited January 24, 20232 yr by Antonio de Sa

You have a lot of info there.

Do you know if there is any way to power the inverter for the "no load consumption" to take it from the power utility grid instead of the batteries?

Hi,

I have exactly the same problem with a Pylontech batt discharging to 0%. I have contacted Growatt support in China but no usable feedback until now.

Nobody in this forum mentioned which firmware is in use. I still have 067.01.104.
Anybody updated to the 'silent' firmware ? I guess in bypass mode the consumption is mainly caused by the fans. If they run slower, the overnight consumption
should drop.
Anybody with a more new firmware ?

BR, Oliver

Hello,