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Is my Axpert King destroying my Pylontech battery?


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Hello All,

Curious question for those aware  of the 69 PV & AC battery charging "error" when the battery SOC is 100%, bypasses the input feed.
Now I have the later 71.94 firmware loaded & the PV & AC battery SOC "error" is now just a "warning" - PV/AC input not bypassed every few seconds.

With this fixed in firmware im observing what appears to be the inverter "draining & dumping" power back into the battery in order to overcome the 69 error issue into a warning one (assumption by obverting the battery voltages)

image.thumb.png.5f3faf750d6daa8c1399e0d78b409bbb.png

These "fluctuations" occurs as soon as the battery SOC reaches 100%

image.thumb.png.977bbf94fef231f1a9e6c016fb62c935.png

and here is a zoomed view of the charge/discharge A & battery volts as soon as the SOC reached 100% above.
image.png.b132bc30dd472581464b94c77ecf1286.png
 

Now my question: Is it at all good or bad for the battery volts to fluctuate (power removed & added by the inverter / assumption based on data ) between 53.100V & sometimes as high as 54.200 ?

 

 

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22 hours ago, Proxicon said:

Is it at all good or bad for the battery volts to fluctuate (power removed & added by the inverter / assumption based on data ) between 53.100V & sometimes as high as 54.200 ?

54.2 means 54.2/15 = 3.613 VPC average. This isn't great for the cells, but not bad either. The small charges and discharges are inevitable, and would not be hurting, in my opinion.

However, it would be better for the cells to stay around 3.5 VPC once fully charged, or around 52.5 V total. It would be great if one of you Pylontech guys figured out the commands to send to the Pylontech BMS (via the console port, an RS-232 port different to the main RS-485 data port) to change the float voltage to that 52.5 V. I think that then the inverter-cable-to-BMS system would work well, with good cell longevity, and few if any panic disconnects from the BMS due to the Axpert overshoots.

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  • 4 weeks later...
Posted (edited)
On 2020/12/10 at 11:37 AM, Coulomb said:

3.5 VPC once fully charged, or around 52.5 V total.

Hi @Coulomb, I have added a US3000c to my setup recently just before the x-mas break. With the 3000c as the master the weird dump & charge fluctuation seen from the start of this thread with just the one 2000b battery has gone away.

Im guessing the firmware / settings has improved a little on the newer model battery vs the 2000b

image.thumb.png.665b92cea488983dc5c460d0997770af.png
 

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  • 1 month later...

I'm also seeing this behaviour.

I recently bought a Pylontech US3000B battery, which I've connected to a Voltronic Axpert King 5K inverter (with a small solar array). I've got connectivity between the battery and inverter working. I came to the forums looking for a battery management strategy that will improve the longevity of the battery pack (I only want it as a backup power source).

For now I've set the inverter to only charge the battery pack from solar, with some automation to cut utility power to the inverter after sunrise and restore utility power when the SoC hits 50%. In my case I suspect the battery will probably operate between 50% and 80% SoC during the course of most summer days, but I need to test this. This is my thumbsuck first-attempt strategy but I don't know if this is actually good for the longevity of the battery or if this default Axpert behaviour above is better?

RS232 console port is definitely on my investigation list (given that the inverter saturates the RS485 link with data).

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On 2021/02/19 at 11:57 PM, aquarat said:

I'm also seeing this behaviour.

I recently bought a Pylontech US3000B battery, which I've connected to a Voltronic Axpert King 5K inverter (with a small solar array). I've got connectivity between the battery and inverter working. I came to the forums looking for a battery management strategy that will improve the longevity of the battery pack (I only want it as a backup power source).

For now I've set the inverter to only charge the battery pack from solar, with some automation to cut utility power to the inverter after sunrise and restore utility power when the SoC hits 50%. In my case I suspect the battery will probably operate between 50% and 80% SoC during the course of most summer days, but I need to test this. This is my thumbsuck first-attempt strategy but I don't know if this is actually good for the longevity of the battery or if this default Axpert behaviour above is better?

RS232 console port is definitely on my investigation list (given that the inverter saturates the RS485 link with data).

Manufacturers state 6000 cycles at 80% DoC at 25 degrees, so you should be good going from 100% to 20% SoC every day in terms of reaching 6000 cycles.
I run my inverter in SBU mode with solar only for the battery charge source. (Sunny days)
Im a low energy user (15 kWh a day on average / no AC running! ) so my small array carries the base load during the day & charges the battery and the 4.7 kwh usable part of the battery carries the night load until sunrise. 

Depending on how intense the dinner making routine is of course, I sometimes hit 20% SoC about an hour before sunrise where the inverter is set back to grid assist (SUB) & then between 08 am and 10am back to SBU mode.

50 to 80% in your case is very limiting in terms of what a LifePo can serve up, you missing out on 50% & only using 30% of available energy. Its a LifePo not a led acid 🙂

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On 2021/02/20 at 11:48 PM, Isidro said:

Buenas a mi me pasa lo mismo error 69 y no se q hacer e notado q cuando consumes batería se pierde el error y las bateriad no llegan al 100*100 de la carga saben ustedes algún remedio un saludo 

 

Actualice su firmware Kings al firmware más reciente: 71.94 y los 69 problemas que tiene donde se producen las desconexiones de energía fotovoltaica o ca desaparecerán. Encuentre el firmware en esta sección de descarga de foros.

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On 2020/12/10 at 12:37 PM, Coulomb said:

54.2 means 54.2/15 = 3.613 VPC average. This isn't great for the cells, but not bad either. The small charges and discharges are inevitable, and would not be hurting, in my opinion.

However, it would be better for the cells to stay around 3.5 VPC once fully charged, or around 52.5 V total. It would be great if one of you Pylontech guys figured out the commands to send to the Pylontech BMS (via the console port, an RS-232 port different to the main RS-485 data port) to change the float voltage to that 52.5 V. I think that then the inverter-cable-to-BMS system would work well, with good cell longevity, and few if any panic disconnects from the BMS due to the Axpert overshoots.

At 3.6 V you will get an "High" voltage error. Higher than that the BMS gives an "OV", over voltage error...This happens for a day or 2 while it balances when new.

Download Batterview.exe and interrogate the battery directly.

BalancedButOV.PNG

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