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PLEASE HELP - EG4-LL (V1 with updated Victron Firmware) generating Cell Over Voltage at 100% SOC

Cell OV from EG4 BMS_TOOLS software (when the SOC gets to 100%).
Looking at your pic, it is showing pack 1 status is charging. Yet there is 1 cell over 3.7V an 3 cells over 3.8V. Why has your BMS not hit cell over volt at 3.65V?

Can you post a pic of your BMS settings?
 
I would say there's a serious cell imbalance. And yeah, if the bms isn't terminating charge for a cell over-volt, perhaps the settings are out of spec.
 
Well here is a big problem. Your over volt settings NEED to keep any cell from exceeding 3.65V. You can set the warn where you like (3.63V ?).
I'd put the release around 3.63V (this is where the BMS reconnects after going over 3.65V and cutting out).

Screen Shot 2023-03-10 at 9.10.46 AM.png
 
These are SOK bms presets?

EDIT: Oh, EG4 batteries. I was thinking of the other thread.
Still, these are default factory-settings with such high cell voltage?
 
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There is so much in these settings. You should start a thread asking for all these settings from someone who has EG4-LL batteries.
 
I updated the firmware of three EG4-LL 48V (version one with display) batteries with Victron Hex file in order for my Victron Cerbo GX to talk to them (via a CAN-bus cable). Please see my setup photos. The three batteries were fully charged before connecting them in parallel and attaching them to the other Victron components.

The Cerbo GX is seeing the three batteries and it seems the communication is working. However, I am getting high voltage warnings from Cerbo GX, and Float Stopped, Cell OV from EG4 BMS_TOOLS software (when the SOC gets to 100%). I kept lowering the absorption voltage (default 56.8 volt) to 54 where the warnings stopped and resulted to the batteries charging to 99% instead of 100%. It seems, the three EG4-LL batteries aren't charging at the same rate and the first one that gets to 100% SOC starts to generate warnings, and some of the individual cells continue to charge causing the BMS to switch to the protection mode. The EG4 BMS-TOOLS software shows individual cells getting unbalanced (Note: normal Diff voltage between individual cells is about 0.002 volt but at 100% SOC that number jumps to as much as 0.5 volt). The attached screens-captured of EG4 BMS-TOOLS software show cell voltage of 3.896 volt (normally @ 3.3 volt). What do you think that is happening? Is this a normal behavior? Or is something wrong with the firmware update? Thanks so much for your reply… PS. I don't know, if I those warnings were present before updating the firmware because there was no battery communication, and I wasn't looking at the EG4 BMS_TOOLS software in the past.
I have had the exact same issue with my EG4LL V1 batteries. I had the issue both before and after flashing the firmware for sol-ark. I wanted to close loop my batteries, but the batteries tell the inverter to absorb at too high a voltage.

The issue with the battery is the top balance of the battery pack is way out. I too had 0.5V cell differences with OVP kicking in. The problem is due to too high of an absorb voltage setpoint. The setpoints they say to use or that the battery requests are way too high.

You need to find out at what voltage your cells start running and getting out of balance. You can do this just by adjusting your float up until you see the cell difference appear. I had to absorb mine at 54.4V to start out with then over time could raise it by 0.1V as the batteries allowed to not push the cells too high. Doing this you keep the cell stress down and you might hit 100% SOC. Basically your trying to just go high enough to hit 100% SOC.

If you don't need to hit 100% SOC that ok, as it is not necessary to cell balance.

So what you need to do is float your batteries a a level where you worst batteries have some cells balancing. I used 53.8-54.0V, this allowed my highest cell(any over 3.40V) to balance. I tried to keep the highest voltage below 3.5V to be nice to it. You need to do this for a couple months to get it to calm down. The battery does not need to be 100% SOC to balance, so don't worry if it is lower, just need to be above 3.40V.

I have actually fixed my batteries by cycling(using them on solar off grid) and floating them every day for a couple months at about 54.0V, where the highest cell voltage is above 3.40V. It took a long time as I have been waiting on SS for months now(since mid Dec 2022 and still waiting) and figured I'd try to fix it myself.

It seems like it's not working as it takes forever(couple months) but at this point I am able to Absorb at 55.2V if I want. I am able to push them more now and they stay in balance.

The good thing is that they still have the capacity when you do this, so they are fully usable, and you get to know you batteries more than you wanted to.
 
I just got a reply from Ben from Signature Solar that he will look into it. Yes, it seems, the built-in EG4-LL BMS is not terminating charge for a cell over-volt at 100% SOC. I never touched any BMS settings. I didn't even know that those settings can be changed by me. Here are the screen captured (just taken) from EG4 BMS-TOOLS software showing everything is back to normal for PACK ID 1 # 3 which I posted previously. The issue shows up at 100% SOC.
They told me the configuration #'s mean nothing and aren't used by the battery(it makes no sense). It would be nice to be able to customize the protections.

The battery doesn't shut off until 3.90V high cell. If you hit 3.90V this will trigger OVP, this will in turn trigger the BMS to disconnect the output and set the SOC to 100%. The battery will not reconnect until the cell drops to 3.45V.
 
(Note: normal Diff voltage between individual cells is about 0.002 volt but at 100% SOC that number jumps to as much as 0.5 volt). .
You will need to top balance those batteries. Took my EG4 LP4 batteries several weeks of passive balancing before I could push 56.5v. I wasn't in a hurry so maybe once or twice a week when the batteries were near 54.5v i would "top them off" with a grid connection. Now they can hit 57.5 reliably with out Cell OV.
 
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