I was not home for a few hours and saw that the electricity ran out and that the essential load was off, the SOC dropped to 36% as seen in the screenshot and my battery shut down I think. Also, the Sunsynk connect app usually sends a notification if the grid is offline but not anymore due to an update of the app.

SOC discharging and after 36% goes to zero percentage immediately, I believe the battery shutdown.

Battery showing zero SOC

BMS showing battery is zero

Eskom power is off but the Inverter was still online and the battery also as can be seen in the screenshot. I shut down the battery and started it again and it showed 36% SOC, I guess this has something to do with a safety feature to shut down the battery. Do you perhaps know how to change that percentage to shut down the battery to 20% at least as it is set on the inverter to shut down at 20%?

Not sure if I must adjust the below settings,

This looks like a battery SoC calibration issue, perhaps in combination with a battery and/or inverter firmware issue.

What does the inverter BMS screen show when the battery is supposedly at 100%?

This can normally be corrected for the battery by changing the inverter to AGM (voltage) mode and charging the battery using the specified charge voltage of the battery and letting the battery cells balance for a few hours (set the voltages in the screen first before changing modes).

Next would be to try and understand why this is happening in the first place. I presume there is no solar attached?

Your shutdown % is 35% there,lower that to whatever you want it to cut off at (20%?)

1 hour ago, PsyWulf said:

Your shutdown % is 35% there,lower that to whatever you want it to cut off at (20%?)

ShutDown is 20%. The restart value you see there (35%) is when the inverter must power loads back on after being recharged; after the shutdown occurs. There's a nice explanation of this in this thread!

Edited October 12, 20232 yr by JayMardern

What battery are you using and have you experienced this before?

 

Looks like a SoC calibration issue or issue with the battery (BMS or cell).

@AlexTZA Thanks for the information, My Sunsynk inverter has been recently updated to the latest version I believe the battery is also the latest version as I asked the supplier where I bought it. I will test with the AMG V settings and see if that resolves it. I also don't have solar panels at the moment I will be installing that in January.

 

SOC 100% image

@PsyCLown I am using a Magneto 5.12kwh battery and this is a new installation.

Battery information details are attached.

 

User Manual - IMS303 51V Wall Mount Rev6 (2).pdf Parallel Battery Communication-PIN Configuration (2).pdf

@AlexTZA If you guys are able to assist me with what must I set for the AGM V, I did attach the Magneto battery manual.

2 hours ago, Wesley.Davids said:

@AlexTZA Thanks for the information, My Sunsynk inverter has been recently updated to the latest version I believe the battery is also the latest version as I asked the supplier where I bought it. I will test with the AMG V settings and see if that resolves it. I also don't have solar panels at the moment I will be installing that in January.

 

SOC 100% image

@PsyCLown I am using a Magneto 5.12kwh battery and this is a new installation.

Battery information details are attached.

 

User Manual - IMS303 51V Wall Mount Rev6 (2).pdf 640.39 kB · 0 downloads Parallel Battery Communication-PIN Configuration (2).pdf 192.62 kB · 0 downloads

Based off that picture I am going to assume the cells are not balanced as it's showing SoC at 100% but the pack voltage is only 53.5v and for 5.12kWh battery it would likely be 16 cells.

 

I had a similar issue with my Svolt batteries when I got them, however they have since balanced the cells and now I get a pack voltage of over 56v when at 100%

Although I have not experienced issues with the battery just turning off, even when the the cells were imbalanced so that is a bit of a weird one still.

 

Perhaps post some pictures of the cell voltages for interest sake. 

I was actually referring to the inverter side BMS screen, same as you originally posted. A bit strange the battery is requesting a charge voltage that is so much lower than that specified in the datasheet/manual.

Set the float, absorption and equilisation charge voltages to the charge voltage which is 58.4v according to the manual. Let the battery charge to that voltage and stay there/float for a few hours, or a day would be better. You could then switch back to lithium and see what the SoC does during the next discharge.

Edited October 12, 20232 yr by AlexTZA

2 hours ago, AlexTZA said:

I was actually referring to the inverter side BMS screen, same as you originally posted. A bit strange the battery is requesting a charge voltage that is so much lower than that specified in the datasheet/manual.

Set the float, absorption and equilisation charge voltages to the charge voltage which is 58.4v according to the manual. Let the battery charge to that voltage and stay there/float for a few hours, or a day would be better. You could then switch back to lithium and see what the SoC does during the next discharge.

Thanks, @AlexTZA  I have also changed the voltage to 58.4v and will leave it for a day.

I took a screenshot of the BMS screen for you now.

@PsyCLown I took a few screenshots of the battery info I checked and it is 16 cells

    

 

 

 

 

@Wesley.Davids

Hmm. What is the "PackVol" voltage on the battery side now as reported on the battery LCD screen?

 

Edited October 13, 20232 yr by AlexTZA

11 hours ago, Wesley.Davids said:

@PsyCLown I took a few screenshots of the battery info I checked and it is 16 cells

 

    

 

 

 

 

 

3.33v is far from a fully charged cell, monitor it with the new manual charge settings and let's see what happens.

I am going to assume the BMS will go into OVP and show SoC as 100% and that the cells will likely not be balanced - how much of an imbalance is what I am curious about.

 

Do you have a RS232 cable and PBMS tools? Would be nice to log into PBMS tools and check the settings on the BMS and see whether it is doing any balancing.

 

Also are there any UVP records on the BMS? Wondering if the BMS did not turn the battery off due to a cell being undervoltage?

@AlexTZA the "PackVol" is showing 53.49v at the moment.

@PsyCLown At the moment I don't have those tools, but I will try and see if I can get it.