BMS initial physical connection guide

The ZCell Battery Management System (BMS) is a DIN-Rail device that acts as the virtual glue between one or more underlying batteries and an energy system using those batteries.

Fully configurable via any web browser (including on a smartphone) both locally and via secure remote cloud access, the BMS has two primary functions:

• 'Downstream': Monitoring, control management and maintenance orchestration for the attached ZCell/ZBM2 modules (one or more)
• 'Upstream': Signalling of overall battery system status and capability to an energy management system via any or all of the following industry standard protocols:
  • Automatic CANBus status updates using the standard (Lithium-battery-industry) CANBus BMS update protocol (this is the most commonly used interface approach)
  • MODBUS-TCP queries (polling) of key data over TCP/IP
  • JSON or plain text URL-based queries (polling) of data over TCP/IP

Event-based status can be also be expressed to external systems using both the built-in dry-contact relay and/or by sending control commands to external relay modules (both MODBUS-TCP based and USB-direct-attached relay modules are supported)

Numeric data (e.g. state of charge or other key data) can also be sent periodically (i.e. pushed outbound) via MODBUS-TCP write commands to external systems if required.

Left-to-right across the top of the BMS are physical connection terminals as follows:

• Input power 9-65V DC - use a suitable small fuse or circuit breaker for safety
• A dry-contact low-power signalling relay output (functions are programmable via the BMS)
• The CANBus interface to an upstream energy system
• The RS485 interface to communicate with downstream ZCell/ZBM2 modules

Initial commissioning steps (each of these is explained in more detail in separate knowledge base articles in this section):

• Power the unit
• Connect the RS485 path your ZCell/ZBM2 batteries 
• Connect the BMS to the upstream energy system - usually using the CANBus interface terminals on the BMS to a suitably wired CANBus cable. 
• Connect the unit to an Internet network using either the built in ethernet port (preferred) or use the built-in WiFi module

The factory-default configuration for the BMS enables the built-in WiFi module and creates a local access network to reach the BMS for initial configuration.

That default access WiFi network is called 'ZCell BMS' and it has a default password of 'zcellzcell'.

If you connect to that WiFi access network with a client device (including a smartphone) and open a web browser session to the assigned router IP address on port 3000. For instance, if the router IP address you observe is 1.2.3.4, then browse to http://1.2.3.4:3000

The BMS is usually connected to the Internet for local and remote access and monitoring purposes.

The Internet access link for the BMS can be achieved via the built-in ethernet port (preferred) or by reconfiguring the WiFi module (via the Configuration->Network page) to be in client mode anodising that module to access your local WiFi-based Internet access service.

The BMS automatically connects to the Redflow remote access cloud in the presence of a working Internet access path. No firewall changes are needed as this connection is created with a secure outbound https connection.

Once logged in, the best initial configuration approach for a new site is to work through each page in the 'Configuration' menu - top to bottom and in order - and you'll have your batteries up and running in no time.

The key advice is that if you're unsure about a setting is to leave it at its default value, and/or to read the included setting help (hover over the '?' icons on each page). If still unclear or unsure, please call Redflow for direct assistance.

Note that the CANBus interface is on by default and by default sends standard Lithium-BMS compatible CANBus protocol signalling to the upstream energy system.

• The 'ON' LED will light up when power is applied successfully to the BMS.
• The 'CAN' Tx and Rx LEDs will flash when CANBus communication is occurring to the upstream energy system.
• The '485' Tx and Rx LED's will flash when communication is occurring with the downstream ZCell/ZBM2's.

If you get stuck in a situation where the BMS is in accessible (e.g. getting the IP address access parameters wrong  or otherwise), you can achieve a factory reset of the BMS using a locally attached USB keyboard - see the knowledge base article on that topic for details.

[ In the 'todo' list is to provide a video introduction to the initial configuration of a system using the Redflow BMS, but in the first instance, please do just call on Redflow to assist and we'll be happy to do so ]