Rosen 48 volt 200amp/hr loosing Amp/hrs and SOC dropping each day

[Baja John]

Great news. Are you getting the O-V error?

Things are working fine only error though is the OV when the battery is at 96.7 SOC. The loss of 2% is not happening only using one battery. China Tech says Bat 1 BMS board is faulty and they are sending me another. That is supposed to be the cause of the loss.

 

[FilterGuy]

Things are working fine only error though is the OV when the battery is at 96.7 SOC. The loss of 2% is not happening only using one battery. China Tech says Bat 1 BMS board is faulty and they are sending me another. That is supposed to be the cause of the loss.

Well..... that is mostly good news.

Are you using the communications ports or are you running them independently?

 

[FilterGuy]

Things are working fine only error though is the OV when the battery is at 96.7 SOC. The loss of 2% is not happening only using one battery. China Tech says Bat 1 BMS board is faulty and they are sending me another. That is supposed to be the cause of the loss.

As I recall, you have a Bluetooth app for the battery.
* Could you record the voltages for all the cells when the OV occurs? I am wondering how far out of balance the cells are.
* Do you happen to know what brand/model BMS is used and what the balance current is?
* Do you know if there is a setting that allows the balancing to happen even when the battery is not charging?

 

[FilterGuy]

The reason for all of my questions is that I suspect the cells are not balanced and that is causing the OV at the end of the charge. If the BMS has a high balance current, that might correct itself over time, but I would guess the balance current is not very large. Consequently, the BMS may take an extremely long time to bring them in line.

There are many ways to top balance cells, but since the cells are already built into a battery, several of them may be difficult or impossible. Consequently, the best way to get the cells balanced is to get the BMS to balance more of the time (not just when charging). By letting the BMS Ballance over-night while there is no charging, it should bring the cells in line. They may not be fully balanced yet, but they will be much closer. You might find that after a few days, the OV will go away. At that point you can change the BMS settings back to the factory setting.

One more question: Can you tell what the cell over-voltage limit is set to? We may want to set the limit to 3.65 for the above process and once things are balanced take it back down to 3.6 or maybe even lower. (I like to top balance to a voltage slightly higher than I plan to operate the cells)

Here are a couple of videos that talk about some of this stuff for a different model battery:

 

[MisterSandals]

I suspect the cells are not balanced and that is causing the OV at the end of the charge.

Are there separate error codes listed for battery OV vs cell OV?

 

[Baja John]

The reason for all of my questions is that I suspect the cells are not balanced and that is causing the OV at the end of the charge. If the BMS has a high balance current, that might correct itself over time, but I would guess the balance current is not very large. Consequently, the BMS may take an extremely long time to bring them in line.

There are many ways to top balance cells, but since the cells are already built into a battery, several of them may be difficult or impossible. Consequently, the best way to get the cells balanced is to get the BMS to balance more of the time (not just when charging). By letting the BMS Ballance over-night while there is no charging, it should bring the cells in line. They may not be fully balanced yet, but they will be much closer. You might find that after a few days, the OV will go away. At that point you can change the BMS settings back to the factory setting.

One more question: Can you tell what the cell over-voltage limit is set to? We may want to set the limit to 3.65 for the above process and once things are balanced take it back down to 3.6 or maybe even lower. (I like to top balance to a voltage slightly higher than I plan to operate the cells)

Here are a couple of videos that talk about some of this stuff for a different model battery:

Thanks for the info. I am using the BMS from inverter to just he one battery. I am not using bat 1 as can't be accessed via laptop. Don't have blue tooth but I can take some pictures of my cell voltage when the OV warning comes on.
Gonna take me a day or two as my business is taking up alot of my time as not home alot. I will leave it as it is right now till I got more time.

 

[Agmills]

Rosen was recently selling a 15S 48v 200AH so your suspicion is right on. I don't have a Growatt inverter, I'm still running Outback equipment, so I have nothing even remotely intelligent to add.

I have the same setup. Link me

 

[Agmills]

Big thanks going to do the changes tomorrow morning. Will let you know. When you posted

"Since the max charge voltage is 54.75V, we should set the inverter to something slightly less than that.
In my previous post I said 53.25.... but lets bump that up to 53.75."

I am thinking that is program 19 correct? CV charging voltage.

Please don’t do that. Sorry just seeing this forum and it took me about two months to figure this out. As I said msg me when you can

 

[Agmills]

Ok realized your all good now

 

[guidecca]

Can a LiFePO4 3.2v 280Ah cell "ov" because it has been in storage for 10 months? What is the reasoning behind that? Does a voltage of 0.813v indicate "ov" and the cell is still okay? That is what Basen is claiming.

 

[guidecca]

你是他妈的天才

 

[NASSER]

No OV but the warning SCP. Rosen says that is a protection warning. They are so vague. Only using one battery the other has a BMS board faulty. Working on solution on getting that fixed.

HELLO , DID you fix the warning . iam having same problem with my battery .

 

[SolarDIY2022]

HELLO , DID you fix the warning . iam having same problem with my battery .

This solved my issue.

Set Absorb to 54 volts for the shortest time possible (Depends on your charge controller). Float to 50.3 No BMS communication.
The warning will come on as the voltage rises to 54 and turn off once the voltage falls to float.

Once at least 1 cell in the bank hits 3.6V (54V overall) the %SOC resets to 100. That will also fix your 2% drift.

 

[zne2001]

Hi, I was wondering if you found out what the SCP warnings mean. I also have these batteries with a Victronenergy Quattro 10kVA inverter and if there is this warning on the batteries the inverter does not work. If I connect the 230V distribution network to the inverter for, say, 30 sec. then everything boots up and the SCP error on battery goes away.

 

[FilterGuy]

Hi, I was wondering if you found out what the SCP warnings mean.

On some batteries, SCP error is Short Circuit Protection. The most common cause of this is the inrush current when an inverter is first hooked up. (A 10KW inverter is going to have a huge bank of capacitors right on the DC input. If they are not precharged they will probably trigger an SCP when first hooked up to the battery.

 

[zne2001]

On some batteries, SCP error is Short Circuit Protection. The most common cause of this is the inrush current when an inverter is first hooked up. (A 10KW inverter is going to have a huge bank of capacitors right on the DC input. If they are not precharged they will probably trigger an SCP when first hooked up to the battery.

O.K., I understand that. Three years ago I connected a 5kVA Victron Energy Quattro with PylonTech 2x 2.4kWh batteries (pictured) and the inverter had no such problem. DIP switches on ROSEN batteries only serve to differentiate the addressing of other batteries on the RS485 bus? Is it necessary to set these switches somehow? Thanks

 

[BerSF]

. Not sure if I can open it up to measure the voltage on the cells. It does give me the voltage at the cells on the screen. Hoping that will work for some help.



At 7am on Bat 1 cell #1 voltage is 3311 mV and at 4pm cell #1 voltage is 3580 mV



At 7am on Bat 2 cell #1 voltage is 3313View attachment 88036View attachment 88036View attachment 88037View attachment 88038View attachment 88039 mV and at 4pm cell #1 voltage is 3579 mV



One thing I have noticed that around 10:30 am Bat 1 and 2 both show a OV warning. This is when they no longer charge. Then the warning will go away after a bit as power is being taken from the batteries instead of the solar. Once that happens the warning goes away and they charge till the warning returns. By mid afternoon the warning stays on till sun goes down and the batteries kick in.



I have 12 500watt panels on the roof and they do have enough to run the house all day. But when the battery warning OV goes on inverter switch’s to batteries and amps from panels goes from 79 amps to 9 amps. Sorry the pictures are mixed up.



I did contact Rosen and the Technician through my laptop managed to set Bat 2 to higher SOC and ah but he couldn’t set Bat 1 they are working on a solution for that. My concern is even though they set Bat 2 it still loosing SOC and ah each day as is Bat 1.



Thanks for you time and open to any suggestions. I am still waiting for the tech to get back to me.

That looks a lot like my battery from BCS - is it 15 prismatic cells? If so then drop the charging voltage to 51. I lost 13ah of capacity

 

[Tiger Tom]

That was quite the platinum, concierge, white glove treatment level of help!

I want FilterGuy on seed dial

 

[gramos100]

I just read this thread , as I have the same system of Rosen and Growatt and arrived here researching a recent fault in a similar vein .
System is 3x 9.6kw/200ah Rosen batteries , 2x Growatt SPF 5000TLHVM WPV inverters . 28 x 400 watt PV panels
I have had a few problems over the past 18 months ,
but have never needed the standby generator ! so thats a good review of Rosen Solar.
New problem is with inverter 1 , it is not putting out any charge so inverter 2 is doing all the charging .
Filter guy really seems to have a handle on growatts so could you spare some time to look at this problem , please ?
I also had the OV problem and Gary/Rosen tech , did the same online through my laptop and reset one battery that would only charge to 114 SOC , fascinating watching him rip through the settings online and getting me 200 SOC amps !

 

[MisterSandals]

Filter guy really seems to have a handle on growatts so could you spare some time to look at this problem , please ?

Conjuring @FilterGuy