Hi all. I have a 3kW Axpert 48V inverter, about 5 years old. Upgrading to 2 x 2.4 KVA 52V Pylontech batteries. Can anyone please help with Inverter settings for this setup, as there is no communication between batteries and inverter possible as far as I know?

Edited February 9, 20205 yr by Jaco Fabs

On 2020/02/10 at 1:41 AM, Jaco Fabs said:

Can anyone please help with Inverter settings for this setup, as there is no communication between batteries and inverter possible as far as I know?

That's right, there is no direct cable to let the BMS call the shots; that only happens on selected 5 kVA models.

This is the document that most people start with: https://www.mppsolar.com/manual/Pylontech Lithium/Pylontech inverter setup SOP.pdf

But note these modifications that I suggest: [ edit: now now recommend lower voltages for settings 26 and 27, at 52.5 V and 51.8 V respectively. ]

 

Edited February 19, 20214 yr by Coulomb

Hi, thank you for the feedback, this helps a lot!

On 2020/02/10 at 6:36 AM, Coulomb said:

That's right, there is no direct cable to let the BMS call the shots; that only happens on selected 5 kVA models.

This is the document that most people start with: https://www.mppsolar.com/manual/Pylontech Lithium/Pylontech inverter setup SOP.pdf

But note these modifications that I suggest:

 

HI Coulomb

Which 5kva Axpert uses direct cable to let the bms call the shots? Will the Sol-I-ax-5p do it

On 2020/02/14 at 11:51 PM, Shockin said:

Which 5kva Axpert uses direct cable to let the bms call the shots? Will the Sol-I-ax-5p do it

As of a year ago, only two models, per this page:

https://www.mppsolar.com/v3/pylontech/

They are the PIP-5048GK (Axpert VM III) and PIP-5048MK (Axpert King). 

HI Coulomb

Thanks for the info, how would the axpert SOL-I-AX-5P work with the Pylontech us3000b?  How do you get this inverter and pylontech to talk to each other?

 

33 minutes ago, Shockin said:

Thanks for the info, how would the axpert SOL-I-AX-5P work with the Pylontech us3000b?

Just use the PylonTech as an ordinary battery. Preferably, use a Victron BMV and ICC.

Quote

  How do you get this inverter and pylontech to talk to each other?

You don't. You hope that once the cells are balanced, the BMS will sort out the slight imbalances and protect the cells without needing intervention from the inverter-charger. If it ever does, then the BMS has to get drastic, like disconnect the battery altogether.

What about setting 31. What would be the ideal setting and why?  I want to maximize PV generated power in preference to Utility. I find that even when PV is high a high load switches to bypass on utilility leaving the solar to only charge the battery. 

7 hours ago, @Mak said:

What about setting 31.

Setting 31 (solar power balance) should always be enabled, i.e. SbE. That means it draws more PV power when needed to supply the loads. I have no idea why anyone would ever want to disable that feature. Maybe if you have a very variable load (e.g. 1 kW one second, 3 kW the next) and you find that the inverter overshoots the battery voltage and upsets the battery, then as a bandaid workaround you could disable solar balance, so the PV power was more steady.

It is a stupid setting, but mine is disabled. So this happens: I have more than 4000w of panels. So I limit my maximum PV to just under 4000w with the charging amps. If I have a high load, the total PV Watts will thus also be limited. I only do it to not go over 4000w. With solar flare (I think that's what they call it) I get easily 110% of my panel specs. This works for me as my batteries are charged before I reach 3600w generation and my loads seldom go over 2800w.

I need help to resolve my situation where with a 4kv load. The Inveter is carrying this with Eskom and using solar to charge the battery. How can I get Eskom to carry the load. This is happening at 2 pm when I expect good solar output. See my LCD below. What settings can I change to minimize Eskom use when Solar is available. I already have SBU on Setting 1

On 2020/06/25 at 3:34 PM, @Mak said:

How can I get Eskom to carry the load.

Is there any solution to this problem? 

I found that switching of Eskom forces the loads to be fed by solar and battery, I installed a sonoff switch that disconnects my Eskom supply during the day.

On 2020/06/25 at 3:34 PM, @Mak said:

How can I get Eskom to carry the load. This is happening at 2 pm when I expect good solar output. See my LCD below. What settings can I change to minimize Eskom use when Solar is available. I already have SBU on Setting 1

Please post your full system specs and inverter settings. Then we can see if/how we can help

On 2020/06/24 at 10:12 PM, @Mak said:

I find that even when PV is high a high load switches to bypass on utilility leaving the solar to only charge the battery. 

If you load exceeds your inverter rating (e.g. 6kw load on a 5kW inverter), the Axpert will switch into bypass mode and fully run on utility. It will switch back to SBU/SUB once the load has dropped again in line with the rating

1 hour ago, Gerrie said:

Is there any solution to this problem? 

I found that switching of Eskom forces the loads to be fed by solar and battery, I installed a sonoff switch that disconnects my Eskom supply during the day.

This can be better handled by having the correct settings on the inverter. No need for any external switches

1 hour ago, wolfandy said:

It will switch back to SBU/SUB once the load has dropped again in line with the rating

There is hysteresis; the inverter won't switch back to battery mode unless the load drops to 85% of rated. Another undocumented behaviour. 

 

On 2020/02/10 at 6:36 AM, Coulomb said:

That's right, there is no direct cable to let the BMS call the shots; that only happens on selected 5 kVA models.

This is the document that most people start with: https://www.mppsolar.com/manual/Pylontech Lithium/Pylontech inverter setup SOP.pdf

But note these modifications that I suggest: [ edit: now now recommend lower voltages for settings 26 and 27, at 52.5 V and 51.8 V respectively. ]

 

Hi bro
Just installed Axpect King 5kw + Pylontech US5000 here. I didn't know that it required custom rs485 cable (as I found original from the battery cable pack is not match).
So I used your values to define is as USER battery type. Thank you so much!
But I like to know where you got these values? Does 46V cut-off is not too low for such battery? Is it safe?
26\27 it seems you took from this page https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom
Btw, why they said that Pylontech has 15 cells when usually, AFAIK, LiFePo4 batteries use 16 cells
Thanks in advance

15 hours ago, Vitaliy said:

But I like to know where you got these values

They are largely a compromise between the manufacturer's recommendations (which are definitely too high for imperfect inverters) and settings for my own system, which were chosen by a colleague who knows LFP batteries very well. 

15 hours ago, Vitaliy said:

Does 46V cut-off is not too low for such battery? Is it safe?

It's too low to protect the cells, but the BMS should do that. It's unfortunately necessary to be that low due to some lead acid thinking in the firmware. 

15 hours ago, Vitaliy said:

Btw, why they said that Pylontech has 15 cells when usually, AFAIK, LiFePo4 batteries use 16 cells

I think you'll find that most nominally 48V LFP batteries are 15S, though a few more seem to be using 16S of late. 16S is a better match for the 64V models, which sadly most of them are now. 

Thanks for reply, mate

Pylontech bms, as I got, cuts off at 44.5V. So 46V in this case is defenitely higher. it a bit higher  then 10% soc (3.0v per cell), something about 12-13%. I just not understand why pylontech recommend so high value, 47.5V (3.17v per cell, a bit less then 20% soc)

I used a table from this article https://www.takomabattery.com/understanding-and-apply-of-lifepo4-soc-chart/

I just saw a few videos on YouTube where guys made diy batteries and they used 16s schemes. A small company here seems also use 16s for their self made batteries. So I thought that 16s should be in factory-made batteries too. It was a surprise to me that it is 15s

I'm pretty newby in this area, so a lot of lacks in knowlenge :)