2 hours ago, OzzyMozzy said:

Program 26: 53.2V

please amend to 52.4 - 52.8V it is when equalization happens on pylontech

Edited July 8, 20232 yr by SYC

21 hours ago, SYC said:

please amend to 52.4 - 52.8V it is when equalization happens on pylontech

Balancing can actually start at 50.4v when their is 30mv difference.

I got shouted down for saying 53.2v was too high. I agree with you!

Edited July 9, 20232 yr by Tinbum

Hi @Tinbum

Please see below:

 

Are you using the batteries as a single pack?

YES.

I presume you have a master inverter and a slave inverter connected with an interconnecting communication cable.

CORRECT.

I don't know your inverter but looking at the manual it seems to use RS485 communication to the battery.

RS232 Communication Port.

If your using the US3000C as a master (which you should be) then your communication cable is wrong judging from a picture I found online for that cable. See attached. Have a look in the manual for the US3000C battery for the battery cable end. (pins 1 to 3 should not have any connections on them!).

US3000C is the Master, I will try and source a new cable today or ask a friend to make one.

With regards to dropping the Bulk charge to 52.5V what should the Float charge then be set to?

On 2023/06/07 at 1:45 PM, Gary Waterworth said:

I trust segen for nothing.

I have had 2 invertors warranty rejected. I will never buy anything that is sourced from them.

EISH! I bought thru the power-store and that's where they sourced from.....EISH!

2 hours ago, OzzyMozzy said:

I don't know your inverter but looking at the manual it seems to use RS485 communication to the battery.

RS232 Communication Port.

 

It will be either CAN or RS485 even though the port will do RS232. (Pylontech won't do RS232 inverter communication). (From what I've read before I don't think all those inverters will do CAN even though it's mentioned in the manual. If you do a search on here you may get an idea).

As to float voltage, do a search on here to see what people recommend. (I don't have any manual settings on my inverter, it's all done by the battery communication).

Edited July 12, 20232 yr by Tinbum

Hi @Tinbum

So after a lot of running around trying to find a suitable cable and getting nowhere I spoke to a technician at Mecer/Mustek in Midrand and he said not to use any cable as my inverters don't have a built-in BMS and it could cause problems if I did.

He suggested I set my inverter to;

Setting 02 - 40Amps

Setting 05 - USER DEFINED

Setting 27 - 52.8V

Setting 29 - 46.5V

I then emailed Pylontech China regarding this and this was their response;

We recommend that you use an inverter that can establish communication with the battery.

This inverter can work with our battery without communication, but you need to set the parameters manually.

The maximum charging voltage of the battery should be set to 53.2V, otherwise, the battery will be overcharged and damaged.

For US3000C, the cut-off voltage should be 47V and the max charge/discharge current should be 37A.

I guess my question now is do I need a third party BMS to manage the communication between the inverter and batteries and if so which would be the most relevant if needed?

Hi Ozzy.

I would suggest you have a look Solar Assistant.

It will give you more control over the system.

Hi Jacques Ester

Thanks for the tip, will definitely look into it. 

5 hours ago, OzzyMozzy said:

Hi @Tinbum

So after a lot of running around trying to find a suitable cable and getting nowhere I spoke to a technician at Mecer/Mustek in Midrand and he said not to use any cable as my inverters don't have a built-in BMS and it could cause problems if I did.

He suggested I set my inverter to;

Setting 02 - 40Amps

Setting 05 - USER DEFINED

Setting 27 - 52.8V

Setting 29 - 46.5V

I then emailed Pylontech China regarding this and this was their response;

We recommend that you use an inverter that can establish communication with the battery.

This inverter can work with our battery without communication, but you need to set the parameters manually.

The maximum charging voltage of the battery should be set to 53.2V, otherwise, the battery will be overcharged and damaged.

For US3000C, the cut-off voltage should be 47V and the max charge/discharge current should be 37A.

I guess my question now is do I need a third party BMS to manage the communication between the inverter and batteries and if so which would be the most relevant if needed?

I think this just shows how lucky you have been and how good Pylontech have been to issue you a refund on your damaged batteries. Their warranty says that you must use an approved inverter and I'm pretty certain all their approved inverters require communication between the battery and the inverter.

I would certainly set your inverter to lower than 53.2v as that setting on your inverter has taken the batteries over voltage. In a document that I have previously attached to a post Pylon actually say 52.5 to 53.2v. I'd go with the lower. Remember that without the communication you are relying on the inverter measured voltage which seems inaccurate on your inverter.

I can't recommend any in between BMS as I've never looked into it. So I'd go with the above recommendation or personally I'd swap for a better inverter and sell that one.

Edited July 25, 20232 yr by Tinbum

On 2023/06/09 at 4:54 PM, HenkVDH said:

Hi All,

I had exactly the same issue as above. I bought 3 Pylontech US2000's and had them connected to a Voltronic (Axpert). During this time which was almost 5 years ago the battery went over voltage once or twice according to battery logs (Axpert is not great at controlling battery voltage as there is no feedback from the battery to the inverter on battery voltage (no CAN comms)).I moved over to a Goodwe inverter which controls the voltage to the batteries much better. I added another US2000 a year later and then a US3000 another couple of years later. In November last year i saw an error on the BMS and inspected the batteries. Noticed that one of the US2000's from the orginal 3 was swollen. Removed it from the rack and because of holidays it only went in to Segen January this year.

Feedback from Segen was almost the same as the people above. Over voltage in the first 3 months of the life of the battery, never again after that. No other alarms until the failure in November. Segen also did not want to honour the Warranty. I also argued that the Pylontech documents says that it will protect it self against over voltage, and should disconnect or switch of the battery. If that is not the case and the BMS keeps the battery alive, they should honour the warranty as that is normal operation of the battery. If 54V is so critical then the battery must disconnect itself and wait for manual reset.

All i can say from this is if you have an Axpert or Voltronic type inverter witbout the can comms to the battery and you have Pylontechs, then you probably have experienced over voltage and probably have no warranty.

Very frustrating as the main reason I purchased the batteries was for the 10 year warranty.

Hallo.

I am jumping in here as your comment is the most relevant to my issue.

I bought a Pylontech 3000 that lasted 20 days.  Segensolar denied liability as "the battery overvolted".  I paid for a new BMS.  It lasted 4 days.  It sook it elsewhere (as I was hoping to get some expert opinion to take the seller on) to replace the BMS.  The BMS broke as the "battery discharge was too high".  (Fun fact:  The inverter cannot be set to control the discharge.)  This repair lasted 10 days.  

The relevant background is that my previous battery (a Pylontech US2000) ran without a glitch for three years with my Axpert 4KW/5VA inverter on the same settings.  Every time the 3000 broke, I would install the US2000 and it would run seamlessly.

I do not work with volts and amps.  I work with probabilities and credibility.  It is clear to me (at least) that the only differential is the battery (and not the operator, inverter or anything else).

I hope for the sake of everyone who has these problems, that some "expert" can figure out what the problem is so that a warranty does not need to be discretionary.

The wording in the Pylontech information sheet is clearly that the BMS protects the battery.  It is of little value if the BMS breaks every time it protects the battery.  Replacement is about R5000. 

I sit with a broken battery that I am dread to have fixed because there is absolutely no guarantee what the real problem is.

I would appreciate any insight.

Hi there

My advice would be to contact [email protected] and send him the data sheets that SegenSolar would have sent you to prove whether your battery was overcharging or not.

Alternatively you can post the data sheets here and ask the forum to comment on them, that's what I did as I literally had no idea what they meant.

There are some very clever, very generous people on here and they saved me a fortune...

I have a friend with a Sunsynk 8kw and  Pylontec US3000's. He is concerned about over voltage charging the batteries in the case of a BMS comms failure. 

Can someone tell me what the  Float V, Absorption V & Equialisation V's  should be set for to be on the conservative side of things? 

8 minutes ago, Sc00bs said:

I have a friend with a Sunsynk 8kw and  Pylontec US3000's. He is concerned about over voltage charging the batteries in the case of a BMS comms failure. 

Can someone tell me what the  Float V, Absorption V & Equialisation V's  should be set for to be on the conservative side of things? 

Refer for a part answer to the post from @Tinbum on 25 July. 

On 2023/06/14 at 8:10 PM, Steve87 said:

Guys I hate to say that one is better than the other. But that is one big reason to buy a FreedomWon battery. Local support & they entertain your battery issue should it arise. Why buy a product that has no local OEM presence. Another issue: A BMS is designed to protect whatever is thrown at it. Complete rubbish that the BMS cannot do this job, then they say you have cooked the Battery. 

I'm sorry I just can't accept that statement, otherwise it's not up to the task to begin with. 

I'm not saying one is better than the other but having dealt with FreedomWon, they have provided investigation, service as well as facilitated return of the units to the labs to service cells & BMSs. 

Must admit it's shameful to see ppl spend money then request support the get it refused. 

 

I hope @SEGEN SOLAR take notice of such comments coming from you.

It just seems its too easy to say over voltage and not always showing the proof or providing guidance. 

1 hour ago, Scorp007 said:

Refer for a part answer to the post from @Tinbum on 25 July. 

I went through the complete thread and there doesn't seem to be any complete answer and that's why I was asking.

Float V at 52.4 by the looks of things

What about the Absorption V & Equalisation V's, any idea, also 52.4V? 

I have a very similar type of RMA with Segen outstanding at the moment. I will not fully disclose the info out of respect for them to do the right thing. However, I have done so in the past & will not hesitate to do it again should it be required: I will not support any supplier that does not carry out ethical business operations. My RMA will be a test of exactly this fact. 

The stage is well set...

2 hours ago, OzzyMozzy said:

Hi there

My advice would be to contact [email protected] and send him the data sheets that SegenSolar would have sent you to prove whether your battery was overcharging or not.

Alternatively you can post the data sheets here and ask the forum to comment on them, that's what I did as I literally had no idea what they meant.

There are some very clever, very generous people on here and they saved me a fortune...

They have been posted in another thread and show overvoltage.

12 minutes ago, Sc00bs said:

I went through the complete thread and there doesn't seem to be any complete answer and that's why I was asking.

Float V at 52.4 by the looks of things

What about the Absorption V & Equalisation V's, any idea, also 52.4V? 

Victron does not apply Equalising on lithium. Bulk charging they suggest 3.5V per cell IIRC. 

This could be a guidance but still 2nd to what the manufacturer suggests. 

Victron also indicates bulk only for a 30min/100Ah capacity. Not sure how balancing would take place in such a short period if balancing is only activated at the higher end of the scale. 

9 minutes ago, Scorp007 said:

Victron does not apply Equalising on lithium. Bulk charging they suggest 3.5V per cell IIRC. 

This could be a guidance but still 2nd to what the manufacturer suggests. 

Victron also indicates bulk only for a 30min/100Ah capacity. Not sure how balancing would take place in such a short period if balancing is only activated at the higher end of the scale. 

Float bulk and equalise are really terms used for lead acid and are really not applicable to lipo. I'd worry if my inverter wanted those settings.

On 2023/06/14 at 8:10 PM, Steve87 said:

Another issue: A BMS is designed to protect whatever is thrown at it. Complete rubbish that the BMS cannot do this job, then they say you have cooked the Battery. 

I'm sorry I just can't accept that statement, otherwise it's not up to the task to begin with. 

Yeah. I had that with the battery I had before my FW. The technicians plugged in some software and showed me cases in the log where charge current had exceeded 125A.

I had 3 problems with that

1) My inverter can't deliver 125A
2) The dates for the log entry predated the installation of my system
3) as Steve says, why didn't the BMS intervene to protect the cells? Protecting the cells is it's prime function.

 

22 minutes ago, Tinbum said:

Float bulk and equalise are really terms used for lead acid and are really not applicable to lipo. I'd worry if my inverter wanted those settings.

Terms are used by Victron. How can I say they in the wrong? 

Voltages are for 4, 8, and 16 cells. 

1 hour ago, Scorp007 said:

Terms are used by Victron. How can I say they in the wrong?

I'm not saying that, It's just a carry over from lead acid and as such is still used but it really isn't applicable to LiPo. That's why Pylontech dont give values for them.

8 hours ago, OzzyMozzy said:

Hi there

My advice would be to contact [email protected] and send him the data sheets that SegenSolar would have sent you to prove whether your battery was overcharging or not.

Alternatively you can post the data sheets here and ask the forum to comment on them, that's what I did as I literally had no idea what they meant.

There are some very clever, very generous people on here and they saved me a fortune...

Thank you.

 

I am sure there are clever and generous people here.  I cannot really argue with whether the battery overcharged or not.  My issue is why the BMS allowed it to overcharge.  Methinks the BMS is to blame but we ask the BMS to tell us what happened.  And, the supplier does not want to accept liability for a "bad" BMS.  How can the consumer ever win?  All I need is a smart person to admit the BMS is to blame for breaking itself...  

20 minutes ago, Grotman said:

Thank you.

 

I am sure there are clever and generous people here.  I cannot really argue with whether the battery overcharged or not.  My issue is why the BMS allowed it to overcharge.  Methinks the BMS is to blame but we ask the BMS to tell us what happened.  And, the supplier does not want to accept liability for a "bad" BMS.  How can the consumer ever win?  All I need is a smart person to admit the BMS is to blame for breaking itself...  

Yes the BMS is supposed to protect the battery but it seems with these inverters the inverters don't control the voltage correctly and the battery BMS is unable to turn the inverter off. Most people have no problems at all but it seems people with this inverter do. I think that says it all.

11 minutes ago, Grotman said:

Thank you.

 

I am sure there are clever and generous people here.  I cannot really argue with whether the battery overcharged or not.  My issue is why the BMS allowed it to overcharge.  Methinks the BMS is to blame but we ask the BMS to tell us what happened.  And, the supplier does not want to accept liability for a "bad" BMS.  How can the consumer ever win?  All I need is a smart person to admit the BMS is to blame for breaking itself...  

After looking at your log file again its apparent the battery underwent abuse for quite a while before it died (about 3 weeks ) where the BMS had to protect itself from over-voltage and it did just that . At some point something its going to give in no matter what BMS ,if its continually being hammered with high voltage for 3 weeks probably not many will survive if i had to guess. It also experienced 61,8A charging rate on the very first day. There are plenty of people this forum that use these batteries with CAN communication with great success and that is what i would recommend you do.  Either get a new inverter that can do that or set your charging voltage and amps down and monitor extensively with something like solar assistant if a new inverter is not an option.