EG4-LL 12v 400ah cell difference?

[Palex]

Hi, I'm new to the forum so excuse me if this has been covered already. I just couldn't find a topic.
I just got this EG4-LL 12v 400Ah battery from Signature Solar. At full charge, there is 0.27v difference between cell2 and cell 3. It seems like a big difference, but is it normal at 100% SOC? Also, there is no temperature reading from cells 3 and 4. I emailed SS tech support but they never responded. Should I be concerned?

 

[offgriddave]

I'm not sure which one you got, but in the video from Will, I think the 24v version, there's only two temperature sensors if I remember?

In the voltage difference, have you cycled it a few times?

I'm curious what you find out!

 

[Palex]

I'm not sure which one you got, but in the video from Will, I think the 24v version, there's only two temperature sensors if I remember?

In the voltage difference, have you cycled it a few times?

I'm curious what you find out!

I got the 12v version - pic below. I've seen screenshots in the forum others have posted of their 24v battery BMS software and they have temp readings for all four cells. I wish SS would confirm on this. I'll try calling them too, since they have not replied to my emails.
This is the second time I charge the battery to 100%. The first time was after unpacking it new. As it discharges the cell.voltages get almost equal within 0.01v.

 

[robby]

Mine had a big Voltage difference on one cell but it went away after a full charge then discharge to 20% SOC then a full recharge again.
They all now balance out at 3mV difference. I have been monitoring it for 5 days and everything is still good.

 

[Palex]

Mine had a big Voltage difference on one cell but it went away after a full charge then discharge to 20% SOC then a full recharge again.
They all now balance out at 3mV difference. I have been monitoring it for 5 days and everything is still good.

Mine come out of balance as they approach 100% SOC. I discharged to 20% and back up to full again and same variance of almost 0.3v. Eventually when the charging is complete, the BMS will balance the cells, but I wonder why would one cell run so high, as high as 3.7v when others are 3.4-3.5v. Here is a shot from cycle #3. I emailed Signature Solar twice but they never replied.

 

[Solar Guy Richard]

Mine come out of balance as they approach 100% SOC. I discharged to 20% and back up to full again and same variance of almost 0.3v. Eventually when the charging is complete, the BMS will balance the cells, but I wonder why would one cell run so high, as high as 3.7v when others are 3.4-3.5v. Here is a shot from cycle #3. I emailed Signature Solar twice but they never replied.

Have you tried contacting our phone support? It this is an actual issue consistently we would like to learn more.

 

[Palex]

Have you tried contacting our phone support? It this is an actual issue consistently we would like to learn more.

Thank you for reaching out SS! No, I only sent two emails, but I will certainly call. And, yes, battery is on fourth cycle and that cell 3 runs away as charge gets closer to 100%. Also, there is that missing temperature for cells 3 and 4. But, I am not sure if there is a sensor for those.

 

[Solar Guy Richard]

Thank you for reaching out SS! No, I only sent two emails, but I will certainly call. And, yes, battery is on fourth cycle and that cell 3 runs away as charge gets closer to 100%. Also, there is that missing temperature for cells 3 and 4. But, I am not sure if there is a sensor for those.

Got it. If there is an issue we will 100% get you taken care of.

 

[Palex]

Got it. If there is an issue we will 100% get you taken care of.

Thank you, I will call in the morning as I think you guys are already closed. I really appreciate the proactive attention here!

 

[robby]

Mine is now back to doing it on three cells at some points. They reach up to 3.7xx Volts and then balance out over a two hour period. I am trying to wire up an RS485 dongle to my PC but I see they have password locked the manual on Signature Solar website and I can find nothing on the Pin outs for the RJ45 connector on the EG4 LL.

 

[Solar Guy Richard]

Mine is now back to doing it on three cells at some points. They reach up to 3.7xx Volts and then balance out over a two hour period. I am trying to wire up an RS485 dongle to my PC but I see they have password locked the manual on Signature Solar website and I can find nothing on the Pin outs for the RJ45 connector on the EG4 LL.

Off the top of my head I believe it’s 78 For the pin out. I have a copy in my office but that’s just off the top of my head.

 

[jberger]

Maybe this will help, I had downloaded it a few weeks ago.
It's probably locked because they are updating it, so YMMV.

 

[robby]

Off the top of my head I believe it’s 78 For the pin out. I have a copy in my office but that’s just off the top of my head.

Thanks, I had gotten it a few minutes after I posted from one of your videos.
I am going to upload some data I pulled as soon as I get a chance.
BTW how do you change the time on the BMS? It is stuck in Nov 2019 and the tab that allows it to be changed seems to have the Save or OK button cut off at the bottom.

 

[robby]

Maybe this will help, I had downloaded it a few weeks ago.
It's probably locked because they are updating it, so YMMV.

Thanks, I am not sure if the 48V LL manual is different but this is a starting point.

 

[Solar Guy Richard]

Thanks, I had gotten it a few minutes after I posted from one of your videos.
I am going to upload some data I pulled as soon as I get a chance.
BTW how do you change the time on the BMS? It is stuck in Nov 2019 and the tab that allows it to be changed seems to have the Save or OK button cut off at the bottom.

I’ll get back if I can find it. Pretty sure that’s a registry entry but will verify Monday.

 

[robby]

I’ll get back if I can find it. Pretty sure that’s a registry entry but will verify Monday.

Hi Richard can you please tell me how to change the clock on the battery. It would not matter to me except for the fact that the BMS logs tons of data and it is being logged under dates in Nov-Dec 2019

 

[Solar Guy Richard]

Hi Richard can you please tell me how to change the clock on the battery. It would not matter to me except for the fact that the BMS logs tons of data and it is being logged under dates in Nov-Dec 2019

Still researching this, unfortunately due to weather and a sick kiddo I was out of the office the entire week.

 

[Solar Guy Richard]

Hi Richard can you please tell me how to change the clock on the battery. It would not matter to me except for the fact that the BMS logs tons of data and it is being logged under dates in Nov-Dec 2019

I just emailed the engineering team, they will hopefully get back to me today with an answer.

 

[jberger]

It would also be helpful to be able to rename the BMS or change the serial number.
I have 3 and they all have the same serial, which makes it harder to find the correct entries in the log files.

 

[Abodyofscience]

Taking your four cell voltages,
computing the InterQuartileRange [.054v] on my Excel spreadsheet,
adding 1.5 x IQR [.081v] to the third quartile [3.572v]
gives 3.653v which is less than the 3.705v
and so this 3.705v is not an outlier.

The "stats people" say, Don't worry.