EG4 LifePower BMS and Signature Solar Support Issues

[Jriccisf]

We have a couple of systems from Signature Solar, all similarly configured with Lifepower4 batteries and Growatt 5000 inverters. One of our systems (with a 6 battery bank) has been acting strangely, with State of Charge going down faster than we would have expected. Last week, we arrived on site and the whole battery bank was drained down to 0% SOC. The inverter was off, but no breakers were popped. We believe we've isolated the issue to one battery, and have been trying to communicate with Signature Solar for support on next steps. @SignatureSolarJess has been very helpful, but we still haven't been able to talk to a tech support person after a week of trying via email and phone...so I'm hoping we might be able to find someone here who's had similar issues and knows of a solution. Jess did forward instructions for deep cycling the batteries, which requires 14 days of charging and discharging the batteries, but this is not feasible since the system is remote and off-grid. Plus, it just doesn't seem like we should have to go to such extremes just to reset the BMS - there has to be a better way!

So, we were able to charge the batteries back up using a Chargeverter. Here's the details of that process, and our findings. Any help would be greatly appreciated!

Here is the original BMS Test reading from the battery. The SOC was showing 0%. But, based on the Voltage reading of 50.6V, we’re guessing it was really at about 16% SOC. One thing we noticed was that Cell #5 was significantly lower than the others.




We hooked the battery up to a Chargeverter, and charge relatively slowly until SOC reached over 30% and the low SOC alarms turned off.





We then turned off the battery and let it sit overnight. The next morning, the SOC and voltage had not changed, so we figured that was a good sign. We then continued to charge the battery until it was full - everything looked good up until around 95%.




Right before hitting 95% SOC, the SOC jumped up to 105.11% and a Cell Over Voltage alarm went off. We could tell that all of the cells were within the same range, except for Cell #5 which was a good bit lower than the others. This was interesting, since cell #5 was also the cell that was also much lower than the others when the battery was at 0% SOC. The other interesting thing was that we did not get a battery over voltage alarm, and the battery was only at 57v.




After letting the battery settle for a bit, the voltage went down to 53.51V (which doesn’t appear to be at 100%). The Cell Over Voltage alarm is now off, and the SOC is still reading 105.11%. We're looking for help on next steps now - is there a way to reset the BMS? Should we put it back in the bank with the other 5 batteries?

 

[marionw]

For EG4 LifePower4 batteries which I have:
You need to get cells to 3.45 volts which is the voltage for when the BMS will start to balance the cells (ParamsSettings Tab). When cells start to balance the cell voltage will be prefixed with (Bal). You need to set the ChargeInverter output voltage to between 55.5 and 56.0 volts as you do not want any cell to get to 3.6 which is the cell overvoltage protection value. Once cells start to balance you will see the SOC set/reset to 100% If you see any cell approaching 3.55 which is the Cell Overvoltage Alarm point, lower the ChargeInverter voltage to maintain charging current but prevent cell overvoltage. If possible disconnect and charge just this battery. At some point you will want to charge and balance all batteries together otherwise some will be a charge source and discharge into others until the batteries are balanced voltage wise but the batteries themselves will not necessarily be balanced cell wise.

 

[EG4_Jared]

We have a couple of systems from Signature Solar, all similarly configured with Lifepower4 batteries and Growatt 5000 inverters. One of our systems (with a 6 battery bank) has been acting strangely, with State of Charge going down faster than we would have expected. Last week, we arrived on site and the whole battery bank was drained down to 0% SOC. The inverter was off, but no breakers were popped. We believe we've isolated the issue to one battery, and have been trying to communicate with Signature Solar for support on next steps. @SignatureSolarJess has been very helpful, but we still haven't been able to talk to a tech support person after a week of trying via email and phone...so I'm hoping we might be able to find someone here who's had similar issues and knows of a solution. Jess did forward instructions for deep cycling the batteries, which requires 14 days of charging and discharging the batteries, but this is not feasible since the system is remote and off-grid. Plus, it just doesn't seem like we should have to go to such extremes just to reset the BMS - there has to be a better way!

So, we were able to charge the batteries back up using a Chargeverter. Here's the details of that process, and our findings. Any help would be greatly appreciated!

Here is the original BMS Test reading from the battery. The SOC was showing 0%. But, based on the Voltage reading of 50.6V, we’re guessing it was really at about 16% SOC. One thing we noticed was that Cell #5 was significantly lower than the others.

View attachment 196523


We hooked the battery up to a Chargeverter, and charge relatively slowly until SOC reached over 30% and the low SOC alarms turned off.

View attachment 196521



We then turned off the battery and let it sit overnight. The next morning, the SOC and voltage had not changed, so we figured that was a good sign. We then continued to charge the battery until it was full - everything looked good up until around 95%.

View attachment 196525


Right before hitting 95% SOC, the SOC jumped up to 105.11% and a Cell Over Voltage alarm went off. We could tell that all of the cells were within the same range, except for Cell #5 which was a good bit lower than the others. This was interesting, since cell #5 was also the cell that was also much lower than the others when the battery was at 0% SOC. The other interesting thing was that we did not get a battery over voltage alarm, and the battery was only at 57v.

View attachment 196524


After letting the battery settle for a bit, the voltage went down to 53.51V (which doesn’t appear to be at 100%). The Cell Over Voltage alarm is now off, and the SOC is still reading 105.11%. We're looking for help on next steps now - is there a way to reset the BMS? Should we put it back in the bank with the other 5 batteries?

View attachment 196522

I suggest updating your batteries' firmware to the latest version and conducting a deep cycle process lasting one to two weeks, ensuring a thorough discharge to 80% depth. To address this, set the inverter to a user-defined state and input the low DC cutoff, float, and bulk charge values from the spec-sheet and once the deep cycle process is done, return to BMS communication. Following these steps should resolve the observed issues.

Link to firmware: https://eg4electronics.com/categori...wer4-48v-100ah-lithium-iron-phosphate-battery

 

[Jriccisf]

I suggest updating your batteries' firmware to the latest version and conducting a deep cycle process lasting one to two weeks, ensuring a thorough discharge to 80% depth. To address this, set the inverter to a user-defined state and input the low DC cutoff, float, and bulk charge values from the spec-sheet and once the deep cycle process is done, return to BMS communication. Following these steps should resolve the observed issues.

Link to firmware: https://eg4electronics.com/categori...wer4-48v-100ah-lithium-iron-phosphate-battery

Thanks Jared.

On the Firmware front - is it possible to update the firmware for just one battery in the bank, or is it required that all batteries have the same firmware?

As for the deep cycle process...this is the first I've ever heard of deep cycling / equalizing a Lithium battery. I was under the impression the BMS would take care of this. Why is this necessary? What can I do to avoid this happening again?

- Can you provide details on how to successfully complete the deep cycle process?
- Do I need to deep cycle the one problematic battery before putting it back in the bank?
- Do I need to deep cycle the other batteries in the bank, and can I do them all together?

 

[Brucey]

Will the next generation of eg4 batteries have active balancing to avoid these kinds of issues?

 

[EG4_Jared]

Thanks Jared.

On the Firmware front - is it possible to update the firmware for just one battery in the bank, or is it required that all batteries have the same firmware?

As for the deep cycle process...this is the first I've ever heard of deep cycling / equalizing a Lithium battery. I was under the impression the BMS would take care of this. Why is this necessary? What can I do to avoid this happening again?

- Can you provide details on how to successfully complete the deep cycle process?
- Do I need to deep cycle the one problematic battery before putting it back in the bank?
- Do I need to deep cycle the other batteries in the bank, and can I do them all together?

I suggest ensuring all batteries are updated to the same firmware version and are connected in the same bank during the correction process. In this case, it's about training the BMS to accurately read the State of Charge when batteries are in parallel. The one to two-week deep cycle isn't particularly necessary; instead, charging the bank once up to the overvoltage protection status of around 57.4v using the user-defined settings for your inverter suffices. However, performing a deep cycle for one to two weeks with the correct settings for the user-defined battery type helps rectify any SOC imbalances.

 

[Jriccisf]

So is it common for a bank of Lifepower4 batteries to get into a state where the BMS can not accurately read SOC? And if so, what would cause this? And why can't the BMS correct for this situation? I thought I was done dealing with equalization issues when I switched to Lithium batteries.

Looking at the original thread, can you tell me what's wrong with my problematic battery? Why did it charge down to zero and take the rest of the batteries with it? And why is it now showing 105%SOC? What do I need to do with this battery before putting it back in the bank with the other 5 batteries?

 

[EG4_Jared]

It's not common for Lifepower4 battery banks to face BMS challenges. However, this can occur due to firmware variations, erratic charging, or cell health disparities. The sudden 105% SOC reading indicates a potential BMS misreading or recalibration issue. For this, I would suggest resetting the BMS with the physical reset switch or a firmware update.

 

[Jriccisf]

OK, I performed a physical reset (twice) and that didn't work, but upgrading the Firmware did.

I'll followup after I'm back onsite and we reintroduce this battery into the larger bank.

Thanks for your help, Jared.

 

[marionw]

First, did you place the new batteries into service without first FULLY charging them.
Most new Lifepo4 batteries are delivered with a 40%-50% SOC. The batteries need to be FULLY charged before placing in service in order to calibrate 100% SOC.

Since you indicated you have a ChargeInverter the easiest way to manage getting your batteries FULLY charged is to charge them individually or all in parallel (or some in parallel) depending on the SOC AND cell voltages as well as Pack voltage of each battery. You certainly can use the Inverter if the battery type is set to User and set the appropriate charge voltages and currents are set. In addition you will want to disable BMS Communications.

The "ParameterSettings" tab will show you what the Cell Balance, Cell Overvoltage Protection and Cell Overvoltage Alarm voltage values are.

You will fight getting all batteries charged if there is a wide separation of charge states between batteries, such as the one that reads 105% SOC. You can charge the batteries with higher voltage (57.6 for example) and higher current but you want to monitor battery charging and when the cells (any cell) start to reach around 3.4 volts you will want to decrease charging voltage to 54.5 to 56 volts. This becomes difficult to manage when charging multiple batteries in parallel. The BMS_Tools software is the best monitor tool you have when charging the batteries. Once you get a batteries cell voltages to around 3.4 you then GENTLY get the battery charged the rest of the way by managing the ChargeInverter (or Inverter) charge voltage. As cells reach 3.45 volts they will start to balance and you will see the BMS reset SOC to 100% and charge current will slowly decrease. This can be a painstaking process and fortunately does not need to be done often (depending of the charge-discharge cycles of your system)

Once you get to this point each battery BMS will have a good reference for 100% SOC. I was using my ChargeInverter with the voltage set to 56.0 volts for the final GENTLE charging. The Cell Overvoltage Alarm for #5 will clear if I cycle the breaker on the battery

 

[Jriccisf]

First, did you place the new batteries into service without first FULLY charging them.
Most new Lifepo4 batteries are delivered with a 40%-50% SOC. The batteries need to be FULLY charged before placing in service in order to calibrate 100% SOC.

Since you indicated you have a ChargeInverter the easiest way to manage getting your batteries FULLY charged is to charge them individually or all in parallel (or some in parallel) depending on the SOC AND cell voltages as well as Pack voltage of each battery. You certainly can use the Inverter if the battery type is set to User and set the appropriate charge voltages and currents are set. In addition you will want to disable BMS Communications.

The "ParameterSettings" tab will show you what the Cell Balance, Cell Overvoltage Protection and Cell Overvoltage Alarm voltage values are.

You will fight getting all batteries charged if there is a wide separation of charge states between batteries, such as the one that reads 105% SOC. You can charge the batteries with higher voltage (57.6 for example) and higher current but you want to monitor battery charging and when the cells (any cell) start to reach around 3.4 volts you will want to decrease charging voltage to 54.5 to 56 volts. This becomes difficult to manage when charging multiple batteries in parallel. The BMS_Tools software is the best monitor tool you have when charging the batteries. Once you get a batteries cell voltages to around 3.4 you then GENTLY get the battery charged the rest of the way by managing the ChargeInverter (or Inverter) charge voltage. As cells reach 3.45 volts they will start to balance and you will see the BMS reset SOC to 100% and charge current will slowly decrease. This can be a painstaking process and fortunately does not need to be done often (depending of the charge-discharge cycles of your system)

Once you get to this point each battery BMS will have a good reference for 100% SOC. I was using my ChargeInverter with the voltage set to 56.0 volts for the final GENTLE charging. The Cell Overvoltage Alarm for #5 will clear if I cycle the breaker on the battery

View attachment 196824

Thanks for the detailed response, @marionw. We always fully charge the batteries and make sure the voltage is VERY close between all batteries before we introduce a new battery into the bank. I'm still not sure what happened in this case to get this battery so far out of whack, but I'm hoping that the firmware update will fix everything.

 

[marionw]

There is a spreadsheet in the zip file you downloaded for the firmware update that lists the changes for each version of the firmware

 

[Brucey]

It's not common for Lifepower4 battery banks to face BMS challenges. However, this can occur due to firmware variations, erratic charging, or cell health disparities. The sudden 105% SOC reading indicates a potential BMS misreading or recalibration issue. For this, I would suggest resetting the BMS with the physical reset switch or a firmware update.

Does this problem also exist in the higher end LL V1/V2 batteries?

 

[Zapper77]

We have a couple of systems from Signature Solar, all similarly configured with Lifepower4 batteries and Growatt 5000 inverters. One of our systems (with a 6 battery bank) has been acting strangely, with State of Charge going down faster than we would have expected. Last week, we arrived on site and the whole battery bank was drained down to 0% SOC. The inverter was off, but no breakers were popped. We believe we've isolated the issue to one battery, and have been trying to communicate with Signature Solar for support on next steps. @SignatureSolarJess has been very helpful, but we still haven't been able to talk to a tech support person after a week of trying via email and phone...so I'm hoping we might be able to find someone here who's had similar issues and knows of a solution. Jess did forward instructions for deep cycling the batteries, which requires 14 days of charging and discharging the batteries, but this is not feasible since the system is remote and off-grid. Plus, it just doesn't seem like we should have to go to such extremes just to reset the BMS - there has to be a better way!

So, we were able to charge the batteries back up using a Chargeverter. Here's the details of that process, and our findings. Any help would be greatly appreciated!

Here is the original BMS Test reading from the battery. The SOC was showing 0%. But, based on the Voltage reading of 50.6V, we’re guessing it was really at about 16% SOC. One thing we noticed was that Cell #5 was significantly lower than the others.

View attachment 196523


We hooked the battery up to a Chargeverter, and charge relatively slowly until SOC reached over 30% and the low SOC alarms turned off.

View attachment 196521



We then turned off the battery and let it sit overnight. The next morning, the SOC and voltage had not changed, so we figured that was a good sign. We then continued to charge the battery until it was full - everything looked good up until around 95%.

View attachment 196525


Right before hitting 95% SOC, the SOC jumped up to 105.11% and a Cell Over Voltage alarm went off. We could tell that all of the cells were within the same range, except for Cell #5 which was a good bit lower than the others. This was interesting, since cell #5 was also the cell that was also much lower than the others when the battery was at 0% SOC. The other interesting thing was that we did not get a battery over voltage alarm, and the battery was only at 57v.

View attachment 196524


After letting the battery settle for a bit, the voltage went down to 53.51V (which doesn’t appear to be at 100%). The Cell Over Voltage alarm is now off, and the SOC is still reading 105.11%. We're looking for help on next steps now - is there a way to reset the BMS? Should we put it back in the bank with the other 5 batteries?

View attachment 196522

You won't like my reply but you just need to top balance that battery...I'll be honest it's going to take weeks.

The only way that the BMS can balance is by bleeding off power from the other 15 cells and its a very slow process.

Next you need to increase your off grid cutoff to 15% or higher. (Until that cell gets close to the other 15, you should limit your disconnect to 15%)

Next update the firmware, if you are using original firmware, a fault code like that can shutdown your inverter.

 

[Zapper77]

You won't like my reply but you just need to top balance that battery...I'll be honest it's going to take weeks.

The only way that the BMS can balance is by bleeding off power from the other 15 cells and its a very slow process.

Next you need to increase your off grid cutoff to 15% or higher. (Until that cell gets close to the other 15, you should limit your disconnect to 15%)

Next update the firmware, if you are using original firmware, a fault code like that can shutdown your inverter.

Now, I would personally just ask for permission to Crack open the battery case and manually top balance that one cell using a variable voltage/amperage charger.

 

[hwy17]

Will the next generation of eg4 batteries have active balancing to avoid these kinds of issues?

Active balancer can't help if the batteries are running from 10-70% every day and never getting in balancing range. Which is normally the problem.

 

[EG4_Jared]

Does this problem also exist in the higher end LL V1/V2 batteries?

While SOC imbalances can occur with various BMS, I have noticed that it is less prevalent with EG4LL V1 and V2 systems. These versions are designed to minimize such issues, considering factors like cell health, charging patterns, and firmware consistency, resulting in more reliable performance. Moreover, through firmware updates, Lifepower4 batteries have seen significant improvements, further enhancing their reliability and performance.

 

[Zapper77]

Does this problem also exist in the higher end LL V1/V2 batteries?

I've been testing 3 LL-S (the newest release) and the BMS and Cells are plug and play.
2 batteries came out nearly perfect on the 1st charge. The 3rd battery was nearly perfect after two days.

With LP4 it can take anywhere between 1 charge and 6 months to get perfect.

 

[Jriccisf]

You won't like my reply but you just need to top balance that battery...I'll be honest it's going to take weeks.

The only way that the BMS can balance is by bleeding off power from the other 15 cells and its a very slow process.

Next you need to increase your off grid cutoff to 15% or higher. (Until that cell gets close to the other 15, you should limit your disconnect to 15%)

Next update the firmware, if you are using original firmware, a fault code like that can shutdown your inverter.

That’s definitely not what I want to hear

Here’s the thing - these systems are remote, off grid installations. It’s impossible for me to babysit a deep cycle process for 14 days. I also can’t bring the whole system down just so I can deep cycle one battery. It really feels like this is a battery malfunction or the result of a poorly designed battery/BMS system. End users should not be required to go through such lengths to get a battery to function properly. It’s also incredibly frustrating to not be able to get reliable support from the vendor or manufacturer.

Anyway - is there any way to complete a deep cycle process with the chargeverter?

 

[Brucey]

If they aren't working right they should be taken back by sig solar for a full refund imo. Asking for weeks or months of babysitting to get things back into balance should not be the responsibility of the purchaser.