Seplos RS485 inverter Voltronic
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Samsonite801
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I know enough to know that I bought the wrong Seplos which mine have CAN bus for the inverter comm, and CAN bus for the backend battery-to-battery comms. Where I was supposed to make a custom request to get the version of the Seplos which has an RS485 for the inverter comms, (which still have a CAN bus for the backend battery-to-battery comms)...
I already have the 4 of mine here now, so since I don't want to buy another one with the RS485 on it, my best attempt is going to be to try an RS485-to-CAN bus module in the cable in between my MPP Solar and the Seplos BMS (since they have the CAN-only interfaces)...
I have the RS485 version with firmware for voltronic, but the thing I don't like is that I have to connect the inverter to the RS485 port and not to the RM485 port as reported in the manual. unfortunately the connection is not stable. so i wanted to compare with someone who uses seplos on voltronic inverter
Samsonite801
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You might also check out this post:
diysolarforum.com
@houseofancients has a Voltronic, he might have some great info as well, since he is well versed with Seplos BMS connected with a Voltronic inverter.
The "Meg" Build
When software is written, it has to be tested to see if it works correctly, and if the rest of the code still functions correctly. Communicating between two devices, each has to be stimulated to produce various message. Especially when one isn't their own, so can't trigger the messages or detect...
diysolarforum.com
@houseofancients has a Voltronic, he might have some great info as well, since he is well versed with Seplos BMS connected with a Voltronic inverter.
You 're making a mistake. The left port (inverter port) can be canbus or RS485 depending of your bms version (check D or C on the sticker). the 2 right ports (battery-to-battery) are dedicated RS485 ports not CANBUS.
that won't work, it is not the same protocol running on top of RS485 and CANBUS interface (it is like trying to get a ip device to talk to ipx device connected on the same LAN) .if you want a RS485 bms version, for your MPP inverter , seplos going to happily swap it for you.
first check your sticker number, what cable are you using, ? can you show your pins wiring on both sides
I have 10D version, but if I connect the inverter to the RM485 port it does not connect to the inverter. the support told me to connect the inverter to RS485A and on bms to set dip switch 1 to on. the connection is not stable with the inverter. so I would like to compare myself with those who use it normally
Samsonite801
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Ok yeah, you're right, I forgot, the 2 right ports are RS485 for the backend BMS-to-BMS communication, my mistake. But my left-most port is CAN bus (which were the wrong ones for me)...
I might ping Seplos and see if they will replace 2 of the units I have for the ones which have RS485 for the left (inverter comms) port.
But I had thought that it was Pylontech running over the port, and CAN vs RS485 is just for the hardware switching protocol, but the language on the layer above that will be Pylontech.
I haven't installed this setup yet, so I haven't toyed with any of it yet in real world.
EDIT:
I think I also heard of someone else here in the forum who used a CAN-to-RS485 converter on an RPi with a Seplos and said they achieved successful communication.
Last edited:
is it seplos who told you to connect your inverter to RS485A ? what do you mean by not stable ? can you draw the wrirring of your cable on each side ?
they are correct?
Attachments
yep, wiring is correct, GND is not need for RS485 port,
BMS
4 - A white
5 - B brown
3/6 - GND
INV
3 - B brown
5 - A white
8 - GND
But sometime GND, helps in noisy signal situation.
Can you try to add a wire for GND => pins 3 or 6 of BMS side connected to pin 8 of inverter side.
is it seplos who told you to connect your inverter to RS485A ?
what do you mean by not stable ?
BMS
4 - A white
5 - B brown
3/6 - GND
INV
3 - B brown
5 - A white
8 - GND
But sometime GND, helps in noisy signal situation.
Can you try to add a wire for GND => pins 3 or 6 of BMS side connected to pin 8 of inverter side.
is it seplos who told you to connect your inverter to RS485A ?
what do you mean by not stable ?
yes seplos told me to connect it like this. maybe because my bms has problems and they don't want to handle it under warranty
That's non sense, should be connected on the bms left port. does your inverter ever recognize the battery ?
Try to add the GND wire
Try to get one of their engineer, they can remotely test the bms if necessary.
if you have a usb2rs484 dongle and are comfortable with linux, you can install this python project and test from your PC. it work with windows also, but have to install python for windows and use COMX port definition instead of /dev/ttyUSBx definition.
github.com
Try to add the GND wire
Try to get one of their engineer, they can remotely test the bms if necessary.
if you have a usb2rs484 dongle and are comfortable with linux, you can install this python project and test from your PC. it work with windows also, but have to install python for windows and use COMX port definition instead of /dev/ttyUSBx definition.
GitHub - Frankkkkk/python-pylontech: Python lib to talk to pylontech lithium batteries 🔋 (US2000, US3000, ...) using RS485
Python lib to talk to pylontech lithium batteries 🔋 (US2000, US3000, ...) using RS485 - Frankkkkk/python-pylontech
github.com
Python:
# dmesg to check the name. of your device name => /dev/ttyUSBx
//for linux
>>> import pylontech
>>> p = pylontech.Pylontech(serial_port='/dev/ttyUSB0', baudrate=9600)
>>> print(p.get_values())
# check your configuration panel to get the device name => COMx
//for windows
>>> import pylontech
>>> p = pylontech.Pylontech(serial_port='COM5', baudrate=9600)
>>> print(p.get_values())
Container:
NumberOfModules = 1
Module = ListContainer:
Container:
NumberOfCells = 16
CellVoltages = ListContainer:
3.306
3.307
3.305
3.305
3.306
3.305
3.304
3.305
3.306
3.306
3.307
3.307
3.308
3.307
3.306
NumberOfTemperatures = 4
AverageBMSTemperature = 29.81
GroupedCellsTemperatures = ListContainer:
29.61
29.61
29.61
29.61
Current = -3.5
Voltage = 49.59
Power = -173.565
RemainingCapacity = 39.5
TotalCapacity = 50.0
CycleNumber = 5
TotalPower = -525.8022
StateOfCharge = 0.79
>>> print(p.get_system_parameters())
Container:
CellHighVoltageLimit = 3.7
CellLowVoltageLimit = 3.05
CellUnderVoltageLimit = 2.9
ChargeHighTemperatureLimit = 33.41
ChargeLowTemperatureLimit = 26.21
ChargeCurrentLimit = 10.2
ModuleHighVoltageLimit = 54.0
ModuleLowVoltageLimit = 46.0
ModuleUnderVoltageLimit = 44.5
DischargeHighTemperatureLimit = 33.41
DischargeLowTemperatureLimit = 26.21
DischargeCurrentLimit = -10.0Samsonite801
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FYI, I just heard back from Seplos rep, and he said that the newest model of their 16s 200a BMS supports both RS485 and CAN bus inverter connection protocols in a single model number.
houseofancients
Solar Wizard
it also includes bluetooth i have been told..
i am happy with the 200a's i have now, but probably will consider them in the future
unfortunately BT, seems to just be connected to the display , not sure you can get more than what is on the display maybe, no way to control anything from BT.
riogrande75
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I'm playing with some seplos V16/10E and some voltronic inverters since a while.
My seller @alibaba sent me the document attached.
As I have some infinisolar/mpp-solar/fsp hybrid inverters, I need the voltronic-bms-box additionally to connect to the bms.
Wit the specified firmware (CAN1101[V16 04 06_PN01_220924_9600]（Voltronic）.ehex) it seems that beside the pylontech protocol "spoken" between multiple bms and to the PC software, it "supports" the so called "LIB" protocol on the RS485 ports as well.
Unfortunately it does still not work, I guess it's because of only zero's coming in the reply:
@houseofancients Can you confirm that, or how does the communication of your voltronic inverters look like on the RS485 bus?
My seller @alibaba sent me the document attached.
As I have some infinisolar/mpp-solar/fsp hybrid inverters, I need the voltronic-bms-box additionally to connect to the bms.
Wit the specified firmware (CAN1101[V16 04 06_PN01_220924_9600]（Voltronic）.ehex) it seems that beside the pylontech protocol "spoken" between multiple bms and to the PC software, it "supports" the so called "LIB" protocol on the RS485 ports as well.
Unfortunately it does still not work, I guess it's because of only zero's coming in the reply:
@houseofancients Can you confirm that, or how does the communication of your voltronic inverters look like on the RS485 bus?
houseofancients
Solar Wizard
never got it to work directly, used a man-in-the-middle solution that never quite worked stable...
and have sold my voltronics since then and switched to a natively supported inverter
riogrande75
New Member
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Ok, thx for letting me know.
So I'd rather spend time to develop a man-in-the-middle protocol converter focused on pylontech.
So I'd rather spend time to develop a man-in-the-middle protocol converter focused on pylontech.
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