Hello, I have two batteries LiFePO4 25.6v 100Ah (Ritar G1) in series, without any communication interface ports.
And the inverter (voltronic vm iii twin 6000w 48v).
The inverter was not recognize batteries gives bp error (now it is working after many try).
So i want to make RS485 or CAN ports if its possible. I think (RS485;CAN) are built-in on BMS board but without com interface ports.
I attached some pictures to identify which BMS connectors is RS485 and CAN?
I hope you can help me and thanks in advance.

Edited August 26, 2025Aug 26 by stannatod

R T G - marking on boards - usualy = RX, TX, Ground

according your photo, its numbered 1, one from this pins is IN, and second OUT to next battery. RS485. ring by multimeter betwen R-R, T-T, G-G - its must be one rs485 bus

Edited August 28, 2025Aug 28 by mamont

unsoldered 4 pin near, called SSLI - look like UART console with ground, tx rx (idk rx-tx), 3.3 V power - like service port for uploading firmware on plant and maybe rs232 console

Edited August 28, 2025Aug 28 by mamont

native software for ritars you can find in my repository : https://github.com/mamontuka/ritar-bms-ha , but i dont know supported this one board or not, but you can do with my United BMS custom register map for HA addon if will get rs485 connection to board, also can be ajusted base battery voltages for HA addon counting and publication to MQTT. at all my addon was produced for 48v batteries but over united bms can be setted custom files for any rs485 connected battery

Edited August 28, 2025Aug 28 by mamont

aslo marking 1,2,3,4 on connector 2 according your photo - looks alike DIP switch battery bus number selector

anyway without DIP switch, battery modbus number will be zero (0) - and you will able see this battery from native service software, but for connection to rs485 gate or inverter, battery must be setted nubmer 1 (master) and next battery connected to rs485 out pins - number 2 for properly working on modbus, inverter modbus id must be higher than your battery count (for example 5) - in another case inverter with modbus id 1 will conflict with master battery with modbus id 1

Edited August 28, 2025Aug 28 by mamont

A and R marking on connector 2 according your photo (where i guess DIP switch) - looks alike Alarm and Ready diods +. they may blink

and SW marking may be enable switch button

Edited August 28, 2025Aug 28 by mamont

3 connector on your proto i cant guess because marking may be from another board side ))

how i think connector 3 on your photo - is temperature sensors, but im not sure, pinout look alike 4 cells thermometers + environment sensor. mos temp sensor usualy soldered on board. but its only guess.

Edited August 29, 2025Aug 29 by mamont

On 2025/08/28 at 3:39 PM, mamont said:

R T G - marking on boards - usualy = RX, TX, Ground

according your photo, its numbered 1, one from this pins is IN, and second OUT to next battery. RS485. ring by multimeter betwen R-R, T-T, G-G - its must be one rs485 bus

On 2025/08/28 at 3:39 PM, mamont said:

R T G - marking on boards - usualy = RX, TX, Ground

according your photo, its numbered 1, one from this pins is IN, and second OUT to next battery. RS485. ring by multimeter betwen R-R, T-T, G-G - its must be one rs485 bus

In battery bms is RS485 are dual channels or only one, i mean transceiver is 2 or 1? Also if you look in picture connector 3 you will see onboard printed (H L) and (A B) may be for (H L CAN; A B RS485)

I try to upload some more pictures to identify but its work.

Connector 3 in photo can be temperature sensors, but i

36 minutes ago, stannatod said:

In battery bms is RS485 are dual channels or only one, i mean transceiver is 2 or 1? Also if you look in picture connector 3 you will see onboard printed (H L) and (A B) may be for (H L CAN; A B RS485)

I try to upload some more pictures to identify but its work.

Usualy Rs485 its one bus, where devices splited by modbus id. But it can be splitted too. On batteries where connected sockets - you will have rs485 IN and OUT ports for master and slave batteries, and rs485 (maybe splitted bus) for connection to inverter near can bus for same but alternative. Battery can be readed by native vendor software or my ritar bms addon - over IN rs485 port(what paraleled with OUT rj45 cocket, without connection to inverter at all.

On factory rj45 rear sockets IN and OUT difference just in crossed tx and rx

H L and A B - realy look alike connector to inverter with can H and L and rs485 AB. If you did mistake with rs485 AB - will be nothing. But can must be connected H-H and L-L or can be hardware troubles and maybe broke

9 hours ago, mamont said:

H L and A B - realy look alike connector to inverter with can H and L and rs485 AB. If you did mistake with rs485 AB - will be nothing. But can must be connected H-H and L-L or can be hardware troubles and maybe broke

On 2025/08/28 at 4:01 PM, mamont said:

aslo marking 1,2,3,4 on connector 2 according your photo - looks alike DIP switch battery bus number selector

anyway without DIP switch, battery modbus number will be zero (0) - and you will able see this battery from native service software, but for connection to rs485 gate or inverter, battery must be setted nubmer 1 (master) and next battery connected to rs485 out pins - number 2 for properly working on modbus, inverter modbus id must be higher than your battery count (for example 5) - in another case inverter with modbus id 1 will conflict with master battery with modbus id 1

I think Ritar battery G3 hasn't DIP switches the add 1 activate and configured by power On/Off button ( pressing for 6 seconds) after connecting terminal coding to last BAT (CAN RJ45 pin 2, 3 short together)

according to menual

https://drive.google.com/file/d/1PI65vDR28mE7Mw02WT_aQThAx3Ma9jf3/view?usp=drivesdk

Edited August 31, 2025Aug 31 by stannatod

so if you have alltime default id 1, maybe DIP selector pin 1 (or inversed pin 4) pulled down to ground (or to + power idk) from factory by soldered onboard circuit ? for example if you have DIP switch - zero number id is all swiches down, last id 15 is all swiches up, id 1 is switch 1 - up (pull to ground or +) 2,3,4 down, number 2 - switch 2 up, 1,3,4 down. Ithink all their batteries have same logic, like in this manual https://github.com/mamontuka/ritar-bms-ha/blob/main/software_and_documentation/Ritar_official_software_and_documentation/documentation/user-guide-rack-type-48v-51.2v-ress-battery-v1.1.pdf and this https://github.com/mamontuka/ritar-bms-ha/blob/main/software_and_documentation/Ritar_official_software_and_documentation/documentation/Ritar_BAT-5KWH-51.2V_User-guide_EN.pdf thats different batteries but selector logic same, in case when no DIP switch at all, i think pin shorted by default to ground or power in this connector, for select id number 1 (master). check this theory by ringing by multimeter pin 1 (or inversed pin 4) to ground in connector or power pin in this connector (sure on turned off board)

if im right in my guess, you will able set id how you need, just in easy way and connect batteries to each other with right modbus ids, and take from id 1 master connection to inverter. and sure all batteries will be joined ESS what will readable from master over original soft or from my addon

Edited August 31, 2025Aug 31 by mamont

also if pin 1 and 2 up 3,4 down - it will be modbus id 3, we need just understand what kind pull up/down used - pin to groud or pin to power

Thank you for your helps, i appreciate

Also i found in battery bms connector 3 next (A B text) there's (ic MAX485)

that makes more identifiable pinout of CAN bus H L and RS485 A B

But the Ritar menual say the battery BMS default ADD is 0, if the battery needs to do communication with inverter or there are 2 or more batteries connect in parallel. it needs set ADD .

and setting configuration needs to *connect CAN terminal resistor (120 ohm) to last battery down RJ45.

* Automatic coding part (pin 2;3 short together) to first battery up RJ45.

*then pressing power button for 6sec.

As its showing in the picure connector 3 have 10 pins i don't know where is pins 2;3

(pin 2 in up (O/F/LED+) down (SWB)

pin 3 in up (O/F) down (SWA)

In Ritar menual "BMS Software old" there's "Dry Conn1;Dry Conn2" can i setup modbus id or ADD master and slave for two batteries by bms software only for each one ?

On 2025/09/23 at 12:10 AM, stannatod said:

Thank you for your helps, i appreciate

Also i found in battery bms connector 3 next (A B text) there's (ic MAX485)

that makes more identifiable pinout of CAN bus H L and RS485 A B

But the Ritar menual say the battery BMS default ADD is 0, if the battery needs to do communication with inverter or there are 2 or more batteries connect in parallel. it needs set ADD .

and setting configuration needs to *connect CAN terminal resistor (120 ohm) to last battery down RJ45.

* Automatic coding part (pin 2;3 short together) to first battery up RJ45.

*then pressing power button for 6sec.

As its showing in the picure connector 3 have 10 pins i don't know where is pins 2;3

(pin 2 in up (O/F/LED+) down (SWB)

pin 3 in up (O/F) down (SWA)

In Ritar menual "BMS Software old" there's "Dry Conn1;Dry Conn2" can i setup modbus id or ADD master and slave for two batteries by bms software only for each one ?

Im already answer about modbus id coding logic (you name it "add"). Several times i say about dip selector. Read my posts.

Edited September 24, 2025Sep 24 by mamont

Connection betwen batteries in ess - NOT OVER CAN ! ritar use rs485 modbus where you need set by dip switches modbus id for each battery. Rs485 and can what going on inverter is splitted from internal ess modbus betwen batteries. Only inverter rs485 output can be joined in some cases to internal ess bus. My english so bad, what you not understand me at all ?

You now have read atleast one battery from vendor software over rs485 ? Can you show screenshots ?

Edited September 24, 2025Sep 24 by mamont

I did not connected the battery bms to RS485 communication interface yet

Your english is very good and simple clear. it my understanding to english my apologies

Edited September 24, 2025Sep 24 by stannatod

39 minutes ago, stannatod said:

I did not connected the battery bms to RS485 communication interface yet

Your english is very good and simple clear. it my understanding to english my apologies

couple posts ago i give all needed links, and tell logic how it works at all. last version 2.80 not have buttons on window bottom, i dont know what you run at all, on your screenshot i see at all not equal soft. i say what bms have OUTPUT TO INVERTER CAN/and/or/rs485 ports, and internal IN and OUT rs485 ports, for uniting ESS (Energy Storage System, 1-15 batteries), rs485=modbus. modbus - have bus id (unit id, battery id, add number - its all SAME meaning). you at first need connect your computer to battery INTERNAL rs485 IN port by last version 2.80 vendor software from links what i give, read this battery in proper way at all. then you need reread post where i say about guessing DIP switches, and find in what kind way modbus id coding works on your board.

p.s. buttons in vendor software window bottom, was in VERY OLD 2021 year version... you realy sure what this prehistoric version support newer batteries ?

Edited September 24, 2025Sep 24 by mamont

My battery is RITAR (generation 1) (lifpo4 25.6v 100ah 8cells) G1 haven't any communication interface ports or On/Off button. But BMS board inside its support CAN bus/RS485 already built-in.

Only generation 2, 3 have CAN/RS485 and others interface. Instead of changing the all BMS boards with supported RS485 port i decided to make the communication interface port for RS485 as long as its built-in on existing BMS board, im only a user "not an engineer" learn many things from your posts.I didn't run anything yet, the picure for BMS Software from the Ritar menual the battery is G1 i don't know whats Software is compatible with its yet

Edited September 24, 2025Sep 24 by stannatod

Hello, please tell me which protocol to set on the growatt spf 5000 es inverter for the battery Ritar BAT-5KWH-51.2V (LV/51.2V/100Ah/5.12kWh/LifePO4)

34 minutes ago, Syavkoo said:

Hello, please tell me which protocol to set on the growatt spf 5000 es inverter for the battery Ritar BAT-5KWH-51.2V (LV/51.2V/100Ah/5.12kWh/LifePO4)

Im not specialist in growatts, just not have they close in direct access for ecperiments, but we can try guess conection type and protocol...

AI tell me :

---

Based on system logic and user experience:

• In Deye inverters, "Lithium Mode 00" generally signifies communication via the CAN-bus interface.

• In Growatt inverters, the protocols for CAN-bus communication are located within the L51-L99 range (in the menu setting 36).

The most likely and frequently used protocol that works with many universal/generic batteries is L52 (this protocol emulates the Pylontech CAN-bus communication).

Recommended Setup Steps:

1. Set the Battery Type to "LI": In the Growatt menu (Program 5), select LI (Lithium Ion).

2. Select Protocol L52: In the automatically opened Program 36 menu, select L52. This is the most common "universal" CAN protocol.

3. Check the Cable: Ensure you are using a standard, straight-through RJ45 Ethernet cable. A straight-through cable is often used for both Growatt and Deye CAN communication.

4. Monitor the Connection: After selecting the protocol, give the system a few minutes. If communication is established, the inverter display should show the correct State of Charge (SOC), and there should be no BMS error codes.

   ---

And... Im pretty sure what :

https://github.com/mamontuka/ritar-bms-ha/tree/main/software_and_documentation/RS485_adapters_and_ethernet_gates/UNDOCUMENTED_WIRING_WITH_DEYE

So, by my logic, you need try find in growatt bms protocol what equal to deye 00 proto (can connection, sma type in ritar battery), and properly pinout for cable to connect with growatt.

Or by same logic try find equal proto for rs485 to inverter connection.

Edited November 22, 2025Nov 22 by mamont

Confirm please if will have success in growatt protocol guess, i will add this way to documentation into my repository documentation

there the connection type is rs485. I tried protocols from 01 to 52. The inverter throws out errors 20 and 04