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

• ESP32 Development board
  • Latest Firmware installed with:
  • Captive portal AP to connect to existing WiFi network
  • Standalone AP mode
  • Web server for standalone management
  • Home Assistant integration
• CAN interface PCB board with:
  • CAN bus transceiver high quality Texas Instruments native 3.3v
  • CAN bus termination selectable with solder jumper, on by default.
  • RJ45 CAN bus connector for Inverter, standard wiring for direct inverter connection pin 4H, 5L
  • JK-BMS 4 pin interface connector
• JK-BMS 4 pin cable supplied
• USB Cable supplied for power and data

Getget said:

Hello, I have bought a ESP32 Wroom, a DC-DC conversion module (to pull power from the JK switch/screen port), RS485 -> TTL converter, TTL -> CAN converter TJA1050.

Can you confirm pinout ?
From JK BMS with RS485 module Yellow -> A+, White B- and from the RS485 transceiver TX -> ESP32 pin 17, RX -> ESP32 pin 16 and then from ESP32 to TJA1050 ESP32 pin 14 -> TJA1050 TX and ESP32 pin 4 -> 4.7kohm -> TJA1050 RX ?

Is this all ok ?
Or maybe for 1 meter of cable lenght I can connect the JK directly to ESP32 ? Which color goes where ? Yellow -> TX or yellow -> RX ?

Thank you

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uksa007 said:

Exciting Announcement.
I Have been busy designing a hardware Plug and play hardware interface to make connection to the BMS plug and play.
Will be available to Patreon members first

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TahitiKnx said:

Hello, does it help to connect different can protocols eachother for example a can 2.0B inverter to another can protocole battery of third party brand thru RJ45 cable ? i am looking for can protocole is for alpha ESS smile 5 batt and need to know what pin are for CAN H and Can L in order to connect to a sofar solar inverteur. can you help ? Facebook Good Wize from French Polynesia

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TahitiKnx said:

Hello, does it help to connect different can protocols eachother for example a can 2.0B inverter to another can protocole battery of third party brand thru RJ45 cable ? i am looking for can protocole is for alpha ESS smile 5 batt and need to know what pin are for CAN H and Can L in order to connect to a sofar solar inverteur. can you help ? Facebook Good Wize from French Polynesia

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Starman said:

Hi on my sofar me3000sp pin 4 is can H and pin 5 is can L.

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uksa007 said:

Hi,
Is your Sofar solar inverter working well using my code eg CAN Goodwe/Pylon?

I should probably start to put a list together of confirmed working inverters.
Can you let me know how you configured the inverter to work correctly?

Thanks.

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Starman said:

Hi yes it works well. I connect via the can port on inverter and select general lithium in the battery parameters. The only issue i have is with the absorption, when I charge it only shows bulk upto 100% and then will stop charging and dosnt absorb. It will balance the cells as they hit 3.45v but then won't absorb. Not sure if my absorption voltage should be set higher or lower. Currently set to 55.2v (which I believe is the voltage you put in the script). Other than that though it works perfect. Thank you for all your effort.

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uksa007 said:

Hi,

Not really following why you need CAN 2.0B eg 29 bit identifiers?

Alpha is normally CAN using the pylon protocol eg CAN 2.0A 11 bit identifiers, as do most inverters.
The normal pins for RJ45 CAN are Pin 4 H, Pin 5 L

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TahitiKnx said:

Thank you, when i connect a sofarsolar inverter with its cable to a n Alpha Ess Battery, the batterie is not recognised.

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Suggests the following, should be similar for your inverter​

TahitiKnx said:

Thank you, when i connect a sofarsolar inverter with its cable to a n Alpha Ess Battery, the batterie is not recognised.

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TahitiKnx said:

Hi, now can H and can L are connected from battery to inverter but inverter dont recognise battery. i notice that amass smile 5 batteri wait for un ground on one rj45 pin and my inverter dont provide any ground thru rj10-rj45 pins

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uksa007 said:

Edit confirmed from another source this is what you need:

Alpha ESS SMILE5-BAT Quick Installation Manual page 6

Suggests the following, should be similar for your inverter​

View attachment 143876
On means switch UP, DIP 2 and 3 ON labels are wrong.

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Starman said:

Hi on my sofar me3000sp pin 4 is can H and pin 5 is can L.

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TahitiKnx said:

ohwww you mean alpha Ess CAN H and Can L are not pin 4 and pin 5 but oin 7 and pin 2 ? if that correct i have to re swapp

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uksa007 said:

Yes you need to swap Alpha seem to use 7 and 2 with the dip switches 2 and 3 ON!

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uksa007 said:

Edit confirmed from another source this is what you need:

Alpha ESS SMILE5-BAT Quick Installation Manual page 6

Suggests the following, should be similar for your inverter​

View attachment 143876
On means switch UP, DIP 2 and 3 ON labels are wrong.

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uksa007 said:

That's what I posted already.

Does it work?

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uksa007 said:

Hi,

The BMS side looks correct, please see here for more info https://github.com/Uksa007/esphome-jk-bms-can#schematics
1m for the TLL cable is probably getting a bit long I would recommend keeping it under 30cm or use the RS485 modules.

The TJA1050 I normally use:
can_tx_pin: GPIO23
can_rx_pin: GPIO22

Regards.

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