Growatt 5000es or eg4 battery issue after freeze?

[lns]

I found the Growatt 5000es did not auto start this morning. I have the inverter set on timer to invert only during a few hours around noon. But every morning, the Growatt should auto start charging after the sun comes on. This morning, it did not start. I had to physically turn off the inverter switch and turn it back on. Battery state of charge should have been above 80% the whole night.
I'm wondering if the battery turned off due to freezing temperatures last night? If so, why didn't the Growatt start itself after the temperature rose? When I manually restarted the Growatt, the screen showed about 7 deg C... not sure if that's the temperature in Growatt or the battery.
Anyone else experienced this?
Also, the Victron inverter I have connected to same battery was online this morning.

Update: Resolved by replacing with a new Growatt unit.

 

[Zwy]

Followed you over here from the other thread. The big thing with PV in cold weather is the VOC of strings will be higher. You do not mention what you have for panels and the specifications plus how many in a series string.

This is the first thing you need to check and run thru the Midnite calculator for VOC.

 

[lns]

Followed you over here from the other thread. The big thing with PV in cold weather is the VOC of strings will be higher. You do not mention what you have for panels and the specifications plus how many in a series string.

This is the first thing you need to check and run thru the Midnite calculator for VOC.

Thanks Zwy for checking with me. I only have 5 x 400w 48voc panels in series.. VOC is well under the 450voc max.
I also waited each day for the temperature and sun to come up...
It seems like from the other threads, a consistent Growatt problem that happens suddenly after a successful period of autostarting everyday.

 

[Zwy]

Thanks Zwy for checking with me. I only have 5 x 400w 48voc panels in series.. VOC is well under the 450voc max.
I also waited each day for the temperature and sun to come up...
It seems like from the other threads, a consistent Growatt problem that happens suddenly after a successful period of autostarting everyday.

Next is settings, float charging voltage is set about 0.5V below bulk. Here is why, you stated the battery still has 80% SOC left in the morning. The way a GW works is bulk charge setting is hit and they SCC will not restart until the float voltage setting is hit.

Bulk setting needs to be set for the start of the SOC knee area of the battery, then float set high enough that float charging begins when PV is available. LFP charge/discharge curve is pretty flat and the only thing the GW knows (without using one of the batteries that communicate) is the battery voltage.

 

[lns]

Next is settings, float charging voltage is set about 0.5V below bulk. Here is why, you stated the battery still has 80% SOC left in the morning. The way a GW works is bulk charge setting is hit and they SCC will not restart until the float voltage setting is hit.

Bulk setting needs to be set for the start of the SOC knee area of the battery, then float set high enough that float charging begins when PV is available. LFP charge/discharge curve is pretty flat and the only thing the GW knows (without using one of the batteries that communicate) is the battery voltage.

I don't think I have access to setting the charge voltages.. I'm using LI setting and Ethernet cable from the Growatt to the EG4 battery. Can I get these charge voltages from the EG4 battery manual?
Btw, when you say "the SCC will not restart until the float voltage setting is hit", but it charges and works fine immediately each day if I just turn off the inverter switch off and back on. Does the Growatt ignore that setting when one resets the inverter?

 

[lns]

These are the charge voltages in the EG4 battery spec sheet:
Voltage 51.2V
Capacity 100Ah
Charging Voltage (Bulk/Absorb) 56.2V (+/- 0.2V)
Float 54V (+/- 0.2V)

Not sure if these are the voltages communicated to Growatt by the EG4 though...
Also, I see that the battery BMS Discharge temperature protection: Temperature Protection <32°F or >131°F (<0°C or >55°C)
In my Growatt manual, setting #7 "Auto restart when over temperature occurs" is disabled by default.
Maybe setting #7 applies to under temperature too?

 

[Zwy]

I don't think I have access to setting the charge voltages.. I'm using LI setting and Ethernet cable from the Growatt to the EG4 battery. Can I get these charge voltages from the EG4 battery manual?

I would disconnect EG4 battery comm from the GW and apply USE settings and see if the problem goes away.

I would use 56.0V for bulk, 55.5 for float temporarily. If the problem goes away, then it probably is a comms/setting problem inherent to the EG4 and GW combination.

Btw, when you say "the SCC will not restart until the float voltage setting is hit", but it charges and works fine immediately each day if I just turn off the inverter switch off and back on. Does the Growatt ignore that setting when one resets the inverter?

What occurs on a reboot the GW will go into Bulk charge, then Float after the Bulk setting is hit.

Float will only start after Bulk completes. Using the Float EG4 battery spec you listed above, 54.0V, the cell voltage would be 3.375V. The problem is the charge/discharge curve of LFP is flat after leaving the knee area at the top and bottom of the curve. Voltage doesn't drop to the Float setting so charging doesn't start. I mentioned this in the other thread, that is why you want Bulk at the start of the upper knee area and Float just below it. Using 55.0 to 56.0V for Bulk with a Float setting 0.5V below Bulk will start the SCC into charging.

 

[lns]

I would disconnect EG4 battery comm from the GW and apply USE settings and see if the problem goes away.

I would use 56.0V for bulk, 55.5 for float temporarily. If the problem goes away, then it probably is a comms/setting problem inherent to the EG4 and GW combination.



What occurs on a reboot the GW will go into Bulk charge, then Float after the Bulk setting is hit.

Float will only start after Bulk completes. Using the Float EG4 battery spec you listed above, 54.0V, the cell voltage would be 3.375V. The problem is the charge/discharge curve of LFP is flat after leaving the knee area at the top and bottom of the curve. Voltage doesn't drop to the Float setting so charging doesn't start. I mentioned this in the other thread, that is why you want Bulk at the start of the upper knee area and Float just below it. Using 55.0 to 56.0V for Bulk with a Float setting 0.5V below Bulk will start the SCC into charging.

Ok, I will test your proposed changes in a couple of days. Tonight will be the first warmer night after freezing nights.. I want to see if the non-autostart has something to do with the BMS temperature protection... going to test with one variable change at a time. Thanks!

 

[lns]

so my issue isn't to do with the temperature protection.
I realized that there's 2 different type of autostart issues being posted.
1) PV charging doesn't autostart
2) Growatt does not turn on when sunlight hits panels. Without this, the AIO cannot function without the battery any more.

My issue is #2 even though I have battery connected because I set the schedule to only invert during certain hours. And after it shuts down for the night, the AIO cannot turn itself back on any more because there's some hardware issue that prevents it to function by PV alone or turn on by PV power.

 

[lns]

Resolved: This was a hardware issue. I replaced the Growatt with a new unit and it correctly started up in the morning when sunlight brought enough voltage/amperage to the unit.