Hi,

I'm not very new to the solar world, but I'm new to this forum that looks to be very helpfull. It is several months that I'm studying this kind of inverters but I cannot solve all my doubts.

 

Introduction:

I'm an experienced firmware engineer, so most of my questions are related to the firmware side.

As far as I know, easun inverters are derived from voltronic inverters, so in all my post I'm doing this assumption. The questions are related to 2 kind of inverters:

1) SMG II 5.6KW 80A with MPPT 120 ~450V 

2) iGrid 5.6KW 100A with MPPT 120 ~450V

 

SMG II 5.6KW 80A with MPPT 120 ~450V

1) Looking to manual it does not support BMS, but if I go to the battery type, I can choose LI1, LI2, LI3 and LI4. I'm assuming that LI4 stands for LiFePo4 and when I select it, a warning  appears on the screen stating "Lithium Battery Communication is failed" (read from printed manual provided)(pdf manual that I have does not mention it). And here there's something wrong. LI4 is not mentioned in the "paper manual" but I can select it and it says a warning mentioned in manual. So I think manual is s*it.

2) Looking at the connection port, I see a USB (printer like) connector: what is its use?

3) I also see an RS232 connector. I think that this RS232 shoud be connected to PC to monitor parameters. But it is not specified the internal wiring. RS232 standard is 2 and 3 for tx and rx and 5 for gnd. But I think it is not compliant to standards.

4) I cannot see any BMS communication port, so how it is supposed to work the LI4 feature?? 🙄🙄🙄

5) I cannot set-up wifi communication. I think the working principle should be this:

    - Inverter acts as access point and mobile connects to that. At this point mobile sends some TCP or UDP packets to exchange credentials to connect to wifi network. The credentials are stored by inverter in its internal eeprom (or flash). The inverter reboots and should connect to router.

I repeated the operation many times but I cannot make the inverter connecting to router. (I tried home router and also hotspot from my mobile, maybe it was a problem with firewall or something like that)

I also thought to locally sinff packets with wireshark to check if credentials are exchanged correctly between app and inverter but I did not do this test 'cause I don't know if inverter can accept multiple connections and don't know how ssid and password are transmitted (plain text or not...)

 

iGrid 5.6KW 100A with MPPT 120 ~450V

1) This guy has BMS communication port and the communication is performed quite well. But I don't know if inverter uses RS485 port or CAN port. Supplier says only uses RS485 port... 

2) What's the priority between these 2 communication ports? can I choose 1 of 2 and expecting to work? In other word, are this interfaces providing the same data? Of course with different mechanisms. As you can see it provides CAN interface. So why supplier says that only RS485 work?

 3) The manual says the fw upgrade procedure using a USB pen drive. But the supplier says it is not possible to use that feature.. IDK why...

4) Suppliers sent me RS485 protocol (attached, maybe could be helpfull for someone). Is it correct? Anyone has CAN protocol for communication?

5) Whats the difference between Pylontech, WECO, Soltar, Lib-3rd party protocols? Can I find them somewhere?

 

Hardware questions 

1) What if I flip phase and neutral of AC input? It may cause a problem? (in case of output grounding connected to neutral output) (parameter 38)

2) What if I flip phase and neutral of AC input? It may cause a problem? (in case of output grounding not connected to neutral output) (parameter 38)

3) Are input and output galvanically isolated?

4) If I work in bypass and want to output a 60HZ - 240. (my input is 50Hz - 230V). Is the inverter able to provide that? In other words, the bypass is only a bridge between input and outputs or there's some control between that? (I prefer not to try becouse I can potentially damage inverter

Conclusion:

I'm feeling that inverters have the same fw, but different hw to enable/disable functionalities. And I'm feeling that even the vendor can't answer to my question, indicating they are only resellers. 

Sorry for the long posts and the crazy number of question, but I hope anyone can answer to a part of them.

 

Thanks,

Marco.

On 2023/03/25 at 6:52 PM, Marco_ said:

As far as I know, Easun inverters are derived from Voltronic inverters, so in all my post I'm doing this assumption.

My working theory is that EASun started out as a clone manufacturer, or possibly clone reseller, but lately have become mostly (solely??) a Voltronics reseller.

On 2023/03/25 at 6:52 PM, Marco_ said:

SMG II 5.6KW 80A with MPPT 120 ~450V

1) Looking to manual it does not support BMS, but if I go to the battery type, I can choose LI1, LI2, LI3 and LI4.

If that's a Voltronic model, the closest thing would be an Axpert MKS III (which still doesn't appear on the Voltronic Power website), but with "enhanced power" (5.6 kW instead of 5.0 kW). But LI1-LI4 is not part of any Voltronic firmware, as far as I know. From vague memory, it might be a Growatt thing. So maybe this is a relabelled GroWatt.

On 2023/03/25 at 6:52 PM, Marco_ said:

3) I also see an RS232 connector. I think that this RS232 shoud be connected to PC to monitor parameters. But it is not specified the internal wiring. RS232 standard is 2 and 3 for tx and rx and 5 for gnd. But I think it is not compliant to standards.

So you mean an 8-pin RJ-45 connector? There is a standard for RS-232 over RJ-45, but Voltronic doesn't use it.

On 2023/03/25 at 6:52 PM, Marco_ said:

4) I cannot see any BMS communication port, so how it is supposed to work the LI4 feature??

Good point. A very few BMSs will communicate over RS-232. Maybe it uses that port?

On 2023/03/25 at 6:52 PM, Marco_ said:

iGrid 5.6KW 100A with MPPT 120 ~450V

All the EASun iGrid models are able to export, i.e. they are on-grid models in Voltronic terms. So these would be InfiniSolars, if they are Voltronic at all. Several of the recent InfiniSolar models look very similar to Axpert off-grid models; I suspect that they use similar or even identical hardware.

Quote

 

1) What if I flip phase and neutral of AC input? It may cause a problem? (in case of output grounding connected to neutral output) (parameter 38)

2) What if I flip phase and neutral of AC input? It may cause a problem? (in case of output grounding not connected to neutral output) (parameter 38)

 

I think it's a really bad idea to do this. Many Voltronic models automatically connect the inverter neutral output to earth when in battery mode (AC-in not used). I note that setting 38 is more or less obsolete now that they do this. Setting 38, as far as I can tell, was to activate an external relay to connect neutral out and earth when the inverter doesn't do it for you.

On 2023/03/25 at 6:52 PM, Marco_ said:

3) Are input and output galvanically isolated?

With nearly all inverters, certainly all Axperts, AC-in and AC-out are not isolated. In many modes, AC-in is connected directly to AC-out via internal relays.

In most inverters, I expect the battery input to be isolated from AC-in and AC-out. Certainly for all Axperts.

PV-in connects either to the battery for low PV voltage models, or to the DC bus for high voltage PV models. So PV-in is never isolated. In most high PV voltage models, including all Axperts with such solar chargers, PV-in has lethal voltages with respect to earth.

On 2023/03/25 at 6:52 PM, Marco_ said:

4) If I work in bypass and want to output a 60HZ - 240. (my input is 50Hz - 230V). Is the inverter able to provide that? In other words, the bypass is only a bridge between input and outputs or there's some control between that? (I prefer not to try becouse I can potentially damage inverter

You can't do that on any Axpert. Yes, in bypass mode, and also in SBU mode, AC-in is connected to AC-out via relays.

Hi Coulomb,

thanks for replies. It's more clear now. It's clear that they are mixing reselling 😂😂😂

Quote

My working theory is that EASun started out as a clone manufacturer, or possibly clone reseller, but lately have become mostly (solely??) a Voltronics reseller.

Somethink like that 😂

Quote

If that's a Voltronic model, the closest thing would be an Axpert MKS III (which still doesn't appear on the Voltronic Power website), but with "enhanced power" (5.6 kW instead of 5.0 kW). But LI1-LI4 is not part of any Voltronic firmware, as far as I know. From vague memory, it might be a Growatt thing. So maybe this is a relabelled GroWatt.

Ok, maybe they are mixing up everything

Quote

So you mean an 8-pin RJ-45 connector? There is a standard for RS-232 over RJ-45, but Voltronic doesn't use it.

I was not aware of the standard on RJ45, but it'n not relevant since they don't use the standards

Quote

Good point. A very few BMSs will communicate over RS-232. Maybe it uses that port?

My theory would be that they are using a up-to-date fw but with an old hardware. RS232 on RJ45 it should be for wifi module (or to let a pc sniff the data). I think that the wifi module is basically a gateway from UART to WIFI and sends data somewhere

Quote

All the EASun iGrid models are able to export, i.e. they are on-grid models in Voltronic terms. So these would be InfiniSolars, if they are Voltronic at all. Several of the recent InfiniSolar models look very similar to Axpert off-grid models; I suspect that they use similar or even identical hardware.

yes, this easun model is able to export

Quote

I think it's a really bad idea to do this. Many Voltronic models automatically connect the inverter neutral output to earth when in battery mode (AC-in not used). I note that setting 38 is more or less obsolete now that they do this. Setting 38, as far as I can tell, was to activate an external relay to connect neutral out and earth when the inverter doesn't do it for you.

Ok

Quote

With nearly all inverters, certainly all Axperts, AC-in and AC-out are not isolated. In many modes, AC-in is connected directly to AC-out via internal relays.

In most inverters, I expect the battery input to be isolated from AC-in and AC-out. Certainly for all Axperts.

PV-in connects either to the battery for low PV voltage models, or to the DC bus for high voltage PV models. So PV-in is never isolated. In most high PV voltage models, including all Axperts with such solar chargers, PV-in has lethal voltages with respect to earth.

Thanks

Quote

You can't do that on any Axpert. Yes, in bypass mode, and also in SBU mode, AC-in is connected to AC-out via relays.

Ok thanks, got it.

 

I forgot to attach BMS protocol. Someone recognizes this RS485 protocol?

 

Thanks for all the answers,

Marco.

SV-IV-Voltronic Inverter and BMS 485 communication protocol 20200325.docx

1 hour ago, Marco_ said:

I forgot to attach BMS protocol. Someone recognizes this RS485 protocol?

 

Wow thanks for the doc. Looks pretty much like Voltronic LIB to me. I assume the greyed out parts are not mandatory (when sniffing LIB I didn't see my inverter request the the greyed out stuff (Axpert King 1) - and my battery (Blue Nova RacPower) also doesn't respond to most of the greyed out (0x10-0x2F, 0x40-0x55) addresses, annoyingly).