If I may be the devils advocate here.....

 I have seen too often where people pair one pylon 3.5kw....or lower to a 5kw or larger inverter and then cry wolf when their battery packs up and the supplier does not want to honour the claim.

Get with it guys, you must at least match the battery to the inverter,s capacity.....as a bare minimum.

On 2023/08/06 at 4:45 PM, Nexuss said:

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.

I accept your advice but my US3000 "survived" and is still surviving on exactly the same settings.  Perhaps I must get the supplier to read the US2000's logs...   

On 2023/08/06 at 4:56 PM, GVC said:

If I may be the devils advocate here.....

 I have seen too often where people pair one pylon 3.5kw....or lower to a 5kw or larger inverter and then cry wolf when their battery packs up and the supplier does not want to honour the claim.

Get with it guys, you must at least match the battery to the inverter,s capacity.....as a bare minimum.

Is this a fact or an opinion? Why will one match a battery to an inverter if he only needs to power two lights during loadshedding? 

On 2023/08/06 at 4:44 PM, Tinbum said:

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.

The BMS is not supposed to turn the inverter off, it has nothing to do with the inverter. You got it very wrong here. The BMS is supposed to shut the battery off, not the inverter 

38 minutes ago, hoohloc said:

Is this a fact or an opinion? Why will one match a battery to an inverter if he only needs to power two lights during loadshedding? 

Power factor of 1:1 will keep you out of trouble. If the inverter however, had a discharge limit that could be programmed, different story but batteries need to be protected if they are installed on an inverter that has the potential to take the battery somewhere it's not rated to go. 

When I mean 1:1 I mean in C rating too. Because the Pylontechs are Half C. 

2 minutes ago, Steve87 said:

Power factor of 1:1 will keep you out of trouble. If the inverter however, had a discharge limit that could be programmed, different story but batteries need to be protected if they are installed on an inverter that has the potential to take the battery somewhere it's not rated to go. 

Protecting the battery is the job of BMS, correct me if I'm wrong. I don't see why a user needs to match the 5kw inverter with 5kwh battery when he only needs to power few devices during power cut. If your load which needs to be backed up is only two 15W lights, a 115w TV and 65w laptop charger, why on earth will I spend a fortune on a 5kwh battery when a 2.4kwh will get me through 4 hours of loadshedding with ease? The blank statement of matching a battery to an inverter doesn't hold. You need to know your needs and if you meet your needs with a 2.4kwh or a 3.5kwh battery, go for it 

7 minutes ago, Steve87 said:

When I mean 1:1 I mean in C rating too. Because the Pylontechs are Half C. 

1C is a nice to have, not really necessary IMHO. I'm not convinced that one needs to draw 100A from a battery. How long will a 5Kwh 1C battery last you if you draw 100A? less than an hour? and how long is loadshedding? Just because a Porsche 911 can do 300km/h, doesn't mean everyone will want to drive that fast. You will be more comfortable driving a VW Golf GTI at 160km/h. You will still have a smile on the face when you accelerate to that speed. My point is, if a battery can discharge at 1C, good for it. Will you discharge at 1C, that is the question and how often? people's needs differ, some are happy to discharge 10A or even less, for the duration of loadshedding. There is no racing there, while some want to race and discharge at 100A for god's sake I still don't know why one will want to do that😂

2 hours ago, hoohloc said:

Is this a fact or an opinion? Why will one match a battery to an inverter if he only needs to power two lights during loadshedding? 

I fully agree and have been ducking stone when I dare mention you add as per your requirements. 

But we also see guys will get all the power out that the inverter can supply and some even trip the inverter knowing what kw they can use. 

But then not many will manage the power the way I do. I use less than 2kwh during LS but do use 0.6kwh per night for the elec blanket. My only real essential load. 

In all these cases, we have a damaged BMS here. I dare say either you need to protect that battery with a suitable DC breaker because otherwise you are doing destructive testing.

I totally agree a good BMS will do a good job of being a watch dog. But let's face it the humble Pylontech is not up to the task. I guess that is slowly becoming fact. 

One of the many reasons I use a massive BMS that can handle 300A. Mainly because it covers the entire range of cells attached to it. But Installing a "Dumb" inverter like an Axpert with zero knowledge of what small battery is attached & the hoping for the best is in my opinion planning to fail. 

I would mitigate the threats by a small DC breaker or have a limit on the OG7.2 & the OG10. I don't consider these dumb inverters at all. 

Each to their own I guess, but I am an installer that installs all sorts of things in ppls homes that have little to no discipline or electric knowledge. But if you happy to accept the risks & baby sit your loads then go for it. But I'm with @GVChere. Size right then you never need to worry or ask questions. 

4 hours ago, hoohloc said:

The BMS is not supposed to turn the inverter off, it has nothing to do with the inverter. You got it very wrong here. The BMS is supposed to shut the battery off, not the inverter 

No, sorry, it's  you who are incorrect, look at the pylontech protocol. The protocol will send error codes for the inverter to react to. That's on top of the actual normal instructions that it sends to the inverter. eg.  by limiting the currents. (0X351 bytes, 2,3,4,5)

(That's if you have a decent inverter. I am using inverters that are over 12 years old that have no problem with Pylontech batteries. That's because they were designed properly and are a quality inverter).

It blatantly obvious that the inverts in this thread can't control the voltage correctly and that's not Pylontechs problem. They say the inverter should be approved and their is a reason for that.

 

Edited August 11, 20232 yr by Tinbum

1 hour ago, Steve87 said:

Each to their own I guess, but I am an installer that installs all sorts of things in ppls homes that have little to no discipline or electric knowledge. But if you happy to accept the risks & baby sit your loads then go for it. But I'm with @GVChere. Size right then you never need to worry or ask questions. 

Totally agree. If your not going to size it right then you need to set / limit the max current in the inverter, if you can.

Edited August 11, 20232 yr by Tinbum

Hi

 

I have had 4 x 2.4kw pylontech batteries approved for replacement, had them installed in Jan 2019. They are crediting me as they don't have stock of the 2.4kw. After reading up on the issues....wondering is there a better battery brand rather than going with pylontech again?

 

I have 5x US2000C installed in Sept-2021 and one of them was faulty with swollen cells in July-2023.

Service logs demonstrated that the unit was not misused and I got a new replacement unit without any discussion.

I have a similar setup and have had the same reply from Sengen. They also sent a screenshot showing that the battery Pwr 0V times was 2319. Surely the BMS is faulty to have allowed this? I am currently waiting for a reply from them regarding this.

 

Well , after 4 years in the business one of my OWN batteries started to fail ... an US3000C , and of course , Pylontech denied warranty claim.
Battery installed in a pack of 8 Pylontech batteries where all other are OK.

We decided to start legal actions against Pylontech... it's now a matter of principle where they simply deny more and more users warranty claims based on BS and no hard evidence.

So if anyone wanna join in a class lawsuit action against them , leave a comment or send me a message.
We started by contacting China State Administration for Market Regulation and China Consumers’ Association and I will start gathering information from other users / resellers that face the same denial of warranty claims. It's now a principle case , I have gone over the loss but Pylontech takes us for a bunch of fools.

Also , I see Servtec in UK started outsourcing the pouches for US2000 for now and US3000 will follow shortly

Replacement Cell: 3.2V 25Ah LiFePO₄ Pouch Cell for Pylontech US2000 & – SERVTEC Battery Accessories & Diagnostic Kits

Hi all. Any updates on this matter? I’ve got one US3000C in a stack of 7 with a swollen cell and warranty being denied. Looking for some information to try and make progress with the claim. Thanks.