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diy solar

JK BMS CAN bus comms now possible for inverters that support Goodwe and Pylontech batteries

Hi, this looks to be a great piece of software/hardware that you have designed, and i would have used it if i wasnt running two jk bmsses in parallel!

My question is:

Is it possible to take the SOC data from one bms and use it to operate a relay? Could i modify your code to do this?
(btw the last time i did any programming was with turbo pascal many years ago! - so im basically a complete newbie now)

Im thinking of using chat gpt and ask it to write the code.. ! Has anyone heard of this a.i? Could help you with any code for running two bmses in parallel?
 
Ucatchmydrift said:
Hi, this looks to be a great piece of software/hardware that you have designed, and i would have used it if i wasnt running two jk bmsses in parallel!
Click to expand...
See here for more info on building larger capacity packs, with the current code.
github.com

Welcome to esphome-jk-bms-can Discussions! · Discussion #1 · Uksa007/esphome-jk-bms-can

? Welcome! If you find this useful please We’re using Discussions as a place to connect with other members of our community. We hope that you: Ask questions you’re wondering about. Share ideas. Eng...
github.com github.com

At this stage I don't have a second JK BMS/set of batteries, so developing code would be difficult and it's not something that I would release without proper testing.
 
uksa007 said:
No, the JK BMS CAN port is not active unless you buy the CAN model and their CAN adaptor, the port is TTL level and the protocol is non standard for energy storage inverters.
There would be no point in converting it to CAN then converting it back to TLL for the ESP32 and then decoding the non standard CAN protocol, and it wouldn't work for most people as they don't buy the CAN model.

My code uses the RS485 port, which is TTL level, enabled by default and can be connected directly to the ESP32.
A second serial port on the ESP32 is connected to the TJA1050 for connection to the inverter.

If you want to extend the distance between the JK BMS and ESP32 you can use RS485 adaptors, which is what I do, makes it easier for development, my ESP32 has a RS485 adaptor and then a long cat5 run to the JK RS485 adaptor in the battery box.
Click to expand...
I have JK-BMS version with CAN. The JK has direct canbus physical layer (not TTL). I tested it. The protocol is different (https://github.com/syssi/esphome-jk-bms/blob/main/docs/BMS-CAN Communication protocol.pdf)
It does not have all the info that is available in RS485. The status message with V,A,SOC is sent every 20ms. Still not fast enough to calculate proper SOC.
 
@uksa007 there's a pull request on github that seems to address an issue. It looks promising though I haven't tested it. Check if it's mergeable
 
diy_addict said:
Its about building my own BMS, so didn't bought yet the inverter. I want to use HV inverter with EV battery.
Click to expand...
Can I ask why you are wanting to use a HV inverter and EV batteries?
My 2c rounded up to 5c is that EV batteries are normally made up of smaller 48v packs in series, so you could use them as LV.
Having said that unless you have some already, the battery chemistry(safety), energy density and cost(cheaper) of Lifepo4 cells is better suited for home storage.
There is more than enough complexity in a Low Voltage DIY home storage solution, using HV and designing your own BMS would seem unnecessarily complex and added risk.
Essentially you maybe trying to reinvent with wheel when there is nothing wrong with the current one.
 
uksa007 said:
Can I ask why you are wanting to use a HV inverter and EV batteries?
My 2c rounded up to 5c is that EV batteries are normally made up of smaller 48v packs in series, so you could use them as LV.
Having said that unless you have some already, the battery chemistry(safety), energy density and cost(cheaper) of Lifepo4 cells is better suited for home storage.
There is more than enough complexity in a Low Voltage DIY home storage solution, using HV and designing your own BMS would seem unnecessarily complex and added risk.
Essentially you maybe trying to reinvent with wheel when there is nothing wrong with the current one.
Click to expand...

Send me a link where i buy LifePo4 cheaper then secondlife EV batteries? Anyway we deviate a bit about the original question. I think LV/HV should depend on total system size etc. For smaller installations i think LV is perfect.

Edit: I already made most of the BMS for my EV planning is now to use it as ESS BMS.
 
diy_addict said:
Send me a link where i buy LifePo4 cheaper then secondlife EV batteries?
Click to expand...
EV batteries are mostly all Lithium Ion, which is not as stable/safe as Lifepo4.
Assume you are in EU/UK?

Eu Warehouse 3.2v 280ah Ev Lf280k Lifepo4 280ah Lithium Ion Solar Battery For Energy Storage Jenny Wu Docan Tech 280 - Buy Lifepo4 Cell,Lifepo4 Battery For Solar Street Light,Lifepo4 Battery Catl Lithium Battery Product on Alibaba.com

Eu Warehouse 3.2v 280ah Ev Lf280k Lifepo4 280ah Lithium Ion Solar Battery For Energy Storage Jenny Wu Docan Tech 280 - Buy Lifepo4 Cell,Lifepo4 Battery For Solar Street Light,Lifepo4 Battery Catl Lithium Battery Product on Alibaba.com
www.alibaba.com
 
Or if you want genuine grade a genuinely from eve, then fogstar:
www.fogstar.co.uk

EVE LiFePO4 280Ah Prismatic Cell (Grade A)

Eve LiFePO4 280Ah Prismatic Cells are ideal for off-grid solar batteries, campervan batteries, and leisure batteries. Grade A cells, full certification, supporting documents are available upon request (UN38.3, Specification Reports & MSDS).
www.fogstar.co.uk www.fogstar.co.uk
 
Greetings, all that information discussed here is very interesting. I would like to know if all this information about the JK bms can be applied to the XW Schneider pro inverters to be able to see it through the insigh home. I have searched without much luck to be able to integrate my JK bms to the Schneider inverter.
 
Hello... could you explain it in more detail, I have the adapter for the can port and the RS485 but I can't get it to communicate with the Schneider pro inverter...thanks
 
Roman59 said:
Hello... could you explain it in more detail,
Click to expand...
Can you be more specific what your question is/what stage you are at eg does it communicate with the BMS ok, have you configured the inverter for pylon CAN?

Please see here for more info on how it needs to be connected and how to install the firmware.
github.com

esphome-jk-bms-can/README.md at main · Uksa007/esphome-jk-bms-can

ESPHome component to monitor a Jikong Battery Management System (JK-BMS) via RS485 or BLE, CAN bus Goodwe/Pylon - esphome-jk-bms-can/README.md at main · Uksa007/esphome-jk-bms-can
github.com github.com
 
ok...so I understand that I have to configure the Schneider inverter for bms pylon tech but how do I connect the JK bms to the inverter?...through which port?...excuse my ignorance but I'm not very good at this, but very receptive to learn...thanks
 
Roman59 said:
ok...so I understand that I have to configure the Schneider inverter for bms pylon tech but how do I connect the JK bms to the inverter?...through which port?...excuse my ignorance but I'm not very good at this, but very receptive to learn...thanks
Click to expand...
Have you read the linked page?
github.com

esphome-jk-bms-can/README.md at main · Uksa007/esphome-jk-bms-can

ESPHome component to monitor a Jikong Battery Management System (JK-BMS) via RS485 or BLE, CAN bus Goodwe/Pylon - esphome-jk-bms-can/README.md at main · Uksa007/esphome-jk-bms-can
github.com github.com

You need a ESP32 to interface them.
It depends on which model JK-BMS you have, as how it is connected to the ESP32, most use the GPS port as per schematic posted in my last post.

There are two methods to connect the BMS to ESP32:
1) Direct method if you have the correct JST connecter for the BMS
2) Use the JK-BMS RS485 adaptor and a seperate RS485 to TTL(3.3v) adaptor.

You then need an TJA1050 CAN module to connect the ESP32 to the inverter CAN port.
Do you have any/all of this?
 
hi...I only have the JK-BMS RS485 adapter...where do I get the TJA1050 CAN module and how do I connect it to the ESP32 to the inverter's CAN port. I'm very interested in learning and being able to integrate the JK bms into my Schneider inverter.. .Thank you
 
Roman59 said:
hi...I only have the JK-BMS RS485 adapter...where do I get the TJA1050 CAN module and how do I connect it to the ESP32 to the inverter's CAN port. I'm very interested in learning and being able to integrate the JK bms into my Schneider inverter.. .Thank you
Click to expand...
Learning involves reading, research, critical thinking, trial and error, if you really want to lean I suggest you start doing this.

This is an advanced project, you will need to have a advanced understanding of electronics, be able to read circuit diagrams, construct circuits, install and configure complex software etc.

TJA1050 CAN module is available from ebay, aliexpress, amazon, and many others, have you heard of google?
https://letmegooglethat.com/?q=where+to+buy+TJA1050+CAN+module

Do not buy the MCP2515 it is more complex to setup.
 
Hi...ok I understand your part, you have to have some skills and knowledge, I thought it could be less complicated. Thank you very much for the time you took with me explaining the steps and what I would need. I ask you, is there any BMS on the market that is recognized by the Schneider inverter without much problem? Thank you again
 
Roman59 said:
I ask you, is there any BMS on the market that is recognized by the Schneider inverter without much problem?
Click to expand...
Can't say for sure as I have not tested it, but Seplos have a BMS with built-in a CAN bus that support pylon tech, that might work.
 
Quick question,
What is the voltage on the vbatt pin on the rs485 connector?

I wonder can the esp32 be powered from it?
 
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