I bought a Pylontech US3000C 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.

Can you post the log files?

32 minutes ago, Grotman said:

I bought a Pylontech US3000C 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.

Can you post the log files?

3 minutes ago, Tinbum said:

Can you post the log files?

Can you post the log files?

This is the second failure.

Thank you for your time.

P23US3000C041109_event_20230725162917 J00519.txt

8 minutes ago, Tinbum said:

Can you post the log files?

Can you post the log files?

This is the first failure.

H220907C30050067_event_20230223094320.txt

10 minutes ago, Tinbum said:

Can you post the log files?

Can you post the log files?

Still the first failure.

H220907C30050067_history_20230223093714.txt

9 hours ago, Grotman said:

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.  

You ran a single US3000C battery on a 4kw inverter ?  These batteries are only good for around 1700w each. From your log files its apparent that your charge voltage is also too high as the pack regularly went up to 54V.  Why did you not run both the US2000 and 3000C batteries?   

14 hours ago, Nexuss said:

You ran a single US3000C battery on a 4kw inverter ?  These batteries are only good for around 1700w each. From your log files its apparent that your charge voltage is also too high as the pack regularly went up to 54V.  Why did you not run both the US2000 and 3000C batteries?   

I initially ran the US2000 alone...  I ran the two together until the US3000 broke.  The US3000 ran alone thereafter.  The system does not really work hard:  Back up for when we shed our load or running the pool pump when the sun generates lots of power.  The inverter is set to the seller's specifications:  53.2V.  It never upset the US2000.  What I mean to say is that there was never an issue with the inverter letting 54V through.  My logic is that the problem is not the inverter but the battery.  Perhaps my ignorance is shining through.  What am I missing?  

If you need this battery repaired speak with @BritishRacingGreen. He has repaired Pylons out of warranty. His a very busy man tho...I can also repair for you assuming the Pylontech BMS is toast. I can retrofit a Quality JBD BMS. That will just do its job without getting broke. 

9 hours ago, Grotman said:

I initially ran the US2000 alone...  I ran the two together until the US3000 broke.  The US3000 ran alone thereafter.  The system does not really work hard:  Back up for when we shed our load or running the pool pump when the sun generates lots of power.  The inverter is set to the seller's specifications:  53.2V.  It never upset the US2000.  What I mean to say is that there was never an issue with the inverter letting 54V through.  My logic is that the problem is not the inverter but the battery.  Perhaps my ignorance is shining through.  What am I missing?  

I dont have much knowledge on Axpert inverters but from what i remember they are known to overshoot the set charging voltage by quite a bit so you maybe want to research that and set it slightly lower. Why that never upset the US2000 i am not sure but it does seem like the newer batteries may be more sensitive to overvoltage breakdowns. So its probably the battery and inverter both to blame. 

On 2023/08/03 at 7:17 AM, Nexuss said:

I dont have much knowledge on Axpert inverters but from what i remember they are known to overshoot the set charging voltage by quite a bit so you maybe want to research that and set it slightly lower. Why that never upset the US2000 i am not sure but it does seem like the newer batteries may be more sensitive to overvoltage breakdowns. So its probably the battery and inverter both to blame. 

@Grotman Yes the Axpert inverters do overshoot charge settings. I will not exceed a setting higher than 52.5 volt. This will prevent exceeding max 54.0 volt for Pylontechs. 3.5volt per cell is more than enough.

Edited August 4, 20232 yr by Chris Louw

On 2023/08/03 at 12:02 PM, Chris Louw said:

@Grotman Yes the Axpert inverters do overshoot charge settings. I will not exceed a setting higher than 52.5 volt. This will prevent exceeding max 54.0 volt for Pylontechs. 3.5volt per cell is more than enough.

Thank you.  This makes me think the newer batteries are not really "more sensitive" but instead bad quality.  Something the consumer should not have to accept.  I wonder if there is a better quality BMS to install - instead of the standard fare.  Three failures are more than enough.  Now to get an installer...

Edited August 6, 20232 yr by Grotman

16 minutes ago, Grotman said:

Thank you.  This makes me think the newer batteries are not really "more sensitive" but instead bad quality.  Something the consumer should not have to accept.  I wonder if there is a better quality BMS to install - instead of the standard fare.  Three failures are more than enough.  Now to get an installer...

I'd change the inverter!!

On 2023/08/02 at 9:23 PM, Steve87 said:

If you need this battery repaired speak with @BritishRacingGreen. He has repaired Pylons out of warranty. His a very busy man tho...I can also repair for you assuming the Pylontech BMS is toast. I can retrofit a Quality JBD BMS. That will just do its job without getting broke. 

Hi. I have a us3000c that needs a bms, where are you based? I'm in Cape town