question

driaan-de-clercq avatar image
driaan-de-clercq asked

FreedomWon - overvoltage in unbalanced battery

Dear all,

We have recentely commisioned two systems where we are experiencing extreme problems with the cerbo GX!

The cerbo is causing the Freedom Won etower and BSL Power wall batteries to overcharge, even tough all the settings were set as per the guidelines of Victron and Freedom won and BSL.

The Cerbo's was working fine the first few days and all of a sudden started to use more energy from the Grid than from solar, even on sunny days. How do we resolve this problem? The customers fustrated with their systems as they do not get their savings!!

All the ess settings is correct with the grid setpoints set to 20W.


One cerbo also does upload any data to VRM even tough it shows on the cerbo that it is connected to the internet and that it is making contact to VRM.

Is this problems related to the current cerbo power supply problem? I did not know about the cerbo power supply problem up to now.

I hope to receive a fast response regarding this poblems! @Guy Stewart (Victron Community Manager) @Daniël Boekel (Victron Energy Staff) @Matthias Lange - DE


Kind regards

Driaan


img-20221027-wa0002.jpgimg-20221027-wa0002.jpg

cerbo gxVRM
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5 Answers
nickdb avatar image
nickdb answered ·

I think you need to read a read a few more manuals.

Ess 1 is minimum soc hit, so are you using batterylife optimised mode? What is the active soc? Is the bms set as the source in the gx setup?

As long as it is ess 1 it will pull from grid.

If you are using batterylife, turn it off.

Else check what the minimum soc is set to.

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driaan-de-clercq avatar image driaan-de-clercq commented ·

@nickdb It shows ESS#1, however the the ess mode is currentely set to optimised without batterylife.

The current SOC is set to 95%

What do you mean with "Is the Is the bms set as the source in the gx setup?"


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nickdb avatar image nickdb ♦♦ driaan-de-clercq commented ·

It is behaving as it should. Lower the minimum soc. At 95% it is going to want to get to near 100% or 100% to discharge again. It only reverts ABOVE minimum soc. It is set too high.

There is no value in running ess set that high. Either set to keep batteries charged or set it lower so ESS can operate properly.

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driaan-de-clercq avatar image driaan-de-clercq nickdb ♦♦ commented ·

@nickdb Your comments are contradicting. But thank you for trying to assist. Ess#1 indicates low SOC, which is not possible as the battery SOC is set to 95%.


I think, but I might be wrong, this has something to do with the powersupply unit of the cerbo's being faulty. With the range of problems we are experiecing on these two sites, and the similarities between the two.

How is it possible for a system to be working correctely when commisioned and after a month or few days, to experience so much problems, without anyone touching the settings?

Like the Cerbo that won't upload data to VRM? Even though it is connected to via ethernet?

We had several Victron specialists strugling for more than two months now trying to solve problem of the one system using more power from the grid than the PV, and still we don't have an answer!img-20221027-wa0003.jpg

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nickdb avatar image nickdb ♦♦ driaan-de-clercq commented ·

You do not understand how ESS or a Cerbo works, I really suggest you read up.

ESS #1 does not mean the battery has a low SOC, it means you have hit the minimum ESS SOC set (95%) and it has not cleared this state, until it clears this state it will pull from grid.

ESS will not clear this state at the set SOC exactly, it has to rise 5% or so (depends on the battery size) to revert to normal ops.

You have incorrectly set the minimum SOC to 95%, and it has not got high enough beyond this to discharge again, so that is what it will do.

Blaming the product for what is poor config is wrong.

With grid loss it would have dropped well beneath this minimum and then struggled to reach the point it could recover.

Lower the SOC in ESS and it will behave again. Like I have said already, there is no possible benefit or reason to run it at 95%. If you want a backup system and no discharge, use a different mode, but ESS won't work right in some setups with a minimum discharge of 95%.

Those batteries can comfortably be set to discharge down to a minimum of 20%, if the system is undersized you can raise this a bit so there is a reserve for grid loss, but if it can't cope with a minimum beneath 95% then this really isn't a working ESS.

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Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @Driaan de Clercq


I've looked at one of your sites, and the Cerbo is doing fine...

The battery is asking for 55.8V charge voltage (CVL) and the Victron system is charging at 55.8V

The problem is: the battery is out of balance (new installation? set to 'keep batteries charged' until the battery balances properly, if it doesn't balance the battery is faulty and needs replacing)

Other batteries send a lower CVL (Charge Voltage Limit) and also a lower CCL (Charge Current Limit) if a cell get's too high, but for some reason this battery does not do that. I'd ask FreedomWon why it doesn't...

As a work around you could lower the charge voltage a bit in the DVCC menu, but really this is a battery issue.

@nickdb already explained you why setting an SOC limit in ESS at 95% is a bad idea.

PS did you consult your distributors about this? you're blaming Victron for all kind of things but I don't see any faults from Victron's side..

screenshot-2022-10-29-142336.png


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driaan-de-clercq avatar image driaan-de-clercq commented ·
Dear Daniël,


Thank you for your response. I simply love Victron products, and we recommend almost all of our customers to install Victron products!

I got the site online yesterday, through much trail and error, and got the ess to work again. Turns out, it was a firmware problem on the Cerbo, which caused the Wifi, Ethernet and and other problems.

Freedwon one previously told us that the new firmware of the cerbo caused the etower batteries to over charge. We managed to solve the problem on one of our other sites by changing the firmware. I decided to change the firmware on this particular site to the same firmware on the other site that worked, however it caused the Wifi, and ethernet to stop working with no data uploading to VRM. I tought the strange behaviour of the cerbo had something to do with the power supply problem of the cerbo.

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Warwick Bruce Chapman avatar image Warwick Bruce Chapman driaan-de-clercq commented ·

The opposite is true.

Until recently there have been increasing problems with FW batteries on Victron. FW requested a change to VenusOS to allow SVS to be able to be enabled for FW batteries. That was released in 2.91.

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pedaaa avatar image pedaaa commented ·

@Daniël Boekel (Victron Energy Staff) :

on one had, you are right, its not Victron to blame for this behaviour.

On the other hand, we still should blame Victron, because you put those batteries on the list of "tested, approved and supported" batteries.

So why Victron does not care, that for example CVL is not dynamically adapted by this type of BMS? So why you still approve this battery?

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Alexandra avatar image Alexandra ♦ pedaaa commented ·
@Pedaaa

Since both sides are always developing products and firmware continuously. Things are always changing.

If Freedom want their products to continue working with Victron then they are responsible for making sure that happens. Since the Victron really only needs to know 3 or maybe 4 things from the bms, Charge y/n disharge y/n being among them. And those needs on the victron side have not changed.

As mentioned before, this system is working for other batteries, something has happaned on Freedom Won side. If their product has a problem working with the Victron, then they are free to update their instructions page and say not to use them. Or if their batteries are too slow to balance so are experiencing runaway voltage issues, also their issue. They can send a do not charge signal to victron and it will stop charging.

BTW probably one of the reasons why they are not really adding so much to their 'approved' list, as somehow a Freedom Won problem has become a Victron problem.

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·
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Warwick Bruce Chapman avatar image
Warwick Bruce Chapman answered ·

We experience issues with nearly every eTower we install on ESS.

Over time we have developed the following:

- Discharge the battery to 50% or less

- DVCC reduce charge voltage to 55.0V

- DVCC reduce charge current to 10A

- Set ESS to Keep Batteries Charged


Let the battery recharge slowly and then let it float on 55V (drop to 54V if you still get alarms) for at least 48 hours. Once that is done and you are not getting alarms, remove the charge current and voltage limits in DVCC.


Monitor. You may need to repeat this.


This is an issue that FW have acknowledged with ESS. They have a cell imbalance but the BMS does not lower the CVL to address that. It stays at 55.8V and a high voltage warning results. It should technically be a warning about a high cell voltage.


I am advised a future BMS update for the eTower will dynamically alter the CVL as needed (like the Orion does in the LiTE batteries). However, that will involve going to the battery and connecting a laptop to it while FreedomWon perform the update. This kind of support from FW is very time consuming in our experience.

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driaan-de-clercq avatar image driaan-de-clercq commented ·

Thank you Warwick, I will definitely try this.

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pedaaa avatar image pedaaa commented ·

I have had similar problems with PaceBMS, bad BMS-parameter settings and inbalance of cells. The internal BMS passive balancer has very low power.

So you hardly have any chance to get it to balance without the use of an external active balancer. Once activly balanced it works better.


But also the standard Cell Overvoltage Alarm&Protect Parameters of the BMS is set too high.

Also CVL is not dynamically adapted, as you say.

I wonder why Victron has approved those batteries with Pace BMS at all?

Are those listed "approved" batteries, tested by Victron at all?? I am doing hard to believe that, after seeing how bad they perform with Stock Firmware and settings.


There have been some BMS Firmware improvements so far, but i would say, we are still not done with all the issues



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Warwick Bruce Chapman avatar image Warwick Bruce Chapman pedaaa commented ·
Hubble, BSL and eTower all use the Pace BMS. All are approved by Victron.
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nickdb avatar image nickdb ♦♦ Warwick Bruce Chapman commented ·
And all have had issues.
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pedaaa avatar image pedaaa nickdb ♦♦ commented ·
yes, thats the point, i wonder why Victron makes a list of "approved" batteries, but some of those use BMS with behaviour thats is not within Victron guidelines.


i am working a lot with BSL and there is some progression. They are really trying to improve.

I appriciate that, and i hope they will sort out the issues, as well as the others using PaceBMS.


But ultimatly, those Batteries should not have been approved by Victron from my point of view, until they solved this issues...

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pedaaa avatar image pedaaa pedaaa commented ·
BTW:

this BMS type cuts the negative side, also the circuit breaker is placed on the negative side.

Is this allowable for Victron point of view at all?

i always thought its not allowed to cut negative for Victron 3phase or parallel systems?!

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Alexandra avatar image
Alexandra answered ·

@ everyone on this thread.... Seeing a common factor here freedom won.

We have BYDs, Pylontecs from US3000 to US5000, BSL, Blue Novas both SSS, DUs and others, long name no can say chinese ones too.

None of them have the overcharge or disobeyed CVL issues you are describing.

So surely if it was a victron issue, then all brands would be experiencing an issue?

If it is a new install, normal to see high voltage alarms so check your individual cell voltages, get them fully charged for a few days for balancing to happen. As has been suggested.

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