Are BMS RS485 & CAN communications generic or battery/inverter specific?

[NicaSol]

New to BMS communications for lifepo4 batteries. Not sure if this is the correct way to ask this. Anyway...

For batteries that use RS485 or CAN to communicate with an inverter, can any battery using RS485/CAN communicate with any inverter that has a RS485/CAN port? Are the connections and protocols(?) generic or specific depending on the battery/inverter combo?

I have to replace a dying KiloVault HAB 7.5 (BMS com not supported with my inverter). My inverter is a Phocos Any-Grid PSW-H-5kW-120/48V. It has 2 BMS ports: 1 CAN/RS485 & 1 RS232). The only battery reasonably available to me (in Nicaragua) is a Genixgreen 5.12kWh 51.2V 100Ah ESS-KS7-16100. It supports CAN & RS485. The vendor/installer is looking into this but of has been taking a long time. Genixgreen only says that their batteries can communicate with a "wide variety of inverters". (inquiries to them taking a long time too). Any guidance welcome. Thanks.

 

[kommando]

The wires and the signals eg V and duration are generic, the info passing down the wires is specific to the battery and the inverter and needs to match. Canbus is the same and used more often.

 

[marionw]

There are two parts to the communication:
1) Hardware
2) Software Protocol

a) Hardware is either CAN, RS485, RS232 or RS232-TTL
The hardware specification defines the physical wire connection between devices and how the data signals are sent over the communication cable as well as the "framing" of the data packets. All devices connected must use the same hardware protocol CAN to CAN or RS485 to RS495. CAN to RS485 will not work.

b) Software Protocol.
The software protocol defines how the "data packets" are formatted and what and where each bit of data (such as SOC or Battery Voltage) are located within the data packet. Protocols such as Pylontech, PACE, Growatt, Victron, LuxPower and others are not compatible with each other. Both (or all) devices connected together must use the same protocol (speak the same language).

Many BMS and Inverters provide for selection (programmable) of a common protocol. Just review your inverter manual for the battery type and communication settings. Review any battery you intend to purchase to see if the batteries communication protocols can be programmed to match your inverter (most likely Pylontech). Also consider whether the battery has any type of monitoring capability that will as a minimum display individual cell voltages, either on an LCD on the battery, Bluetooth or computer based software.

 

[NicaSol]

kommando, marionw, Thanks. Have a better idea how to follow up with vendor/installer (and manufacturer).

 

[NicaSol]

Just to wrap this up. Genixgreen and the vendor have confirmed that a CAN/Pylontech connection is compatible for closed loop communication with my Phocos inverter. After they did reply to my inquiry, Genixgreen has been very helpful with information on the required setup. FYI, they provide a large number protocols for both RS485 and CAN.

 

[NicaSol]

Not quite wrapped up. Wising to confirm what the manual stated, and after a long week trying to get through to Phocos, their Tech Support Manager informed me that Phocos does not support CAN connections. They intended to, wrote up the manual, never did implement CAN, and didn't correct the manual. The manual is incorrect regarding using a CAN connection for anything. Geneixgreen, however, does support various CAN-based protocols, including Pylontech..

 

[robbob2112]

One thing that has me puzzled is that practically nobody mentions terminators when talking about the different busses? Also everyone seems to be using CAT5/5E wire which is 100ohms, but RS-485 is 120ohms for the bus. The terminators are different between can bus and rs-485 as well.... and lets not get into ve.can verse the different vendor implementations of CAN where they seem to just plug it together ...