Configuring ESS and Dynamic Voltage and Current Control (DVCC) for ZCell systems with CANBus


 

These instructions assume that:

  • The installer is already trained in the design and installation of Victron Energy based systems
  • For an on-grid system - that the system has been designed, wired and configured in accordance with the Victron Energy ESS Design and Installation Manual
  • That firmware and software has been upgraded to the minimum required versions (as noted below)
  • The ZCell physical installation has been done and the ZCell BMS is installed and communicating with the ZCell cluster using CANbus [ see separate FAQ item ]
  • If using MultiGrid unit(s), ensure these have been configured and their firmware upgraded in accordance with the separate FAQ item about MultiGrid setup at this link or it may not start up properly : Installing a Victron Energy MultiGrid with ZCell systems

You must upgrade all system elements to at least these versions (or later) for correct system operation and to take advantage of all currently known features/bugfixes from older releases:

  • CCGX / Venus GX needs to be running version 2.12 or later
  • MultiGrid/MultiPlus/Quattro systems need to be upgraded to Firmware 424 or later using VE.Flash.
  • MultiGrid/MultiPlus/Quattro systems need to be running an ESS Assistant version of 016C or later (version 016C was released on 4th July 2018). See https://www.victronenergy.com/live/assistants:how_to_update_an_assistant
  • VE.Direct MPPT solarcharger units (if used) need to be upgraded to Firmware version 1.30 or later using VE.Connect for correct operation (including for successful black-start on DVCC mode from MPPT's alone).
  • The Redflow BMS needs to be running 1.5.1 or later.
  • ZCell batteries need to be running battery firmware 32.17.14 or later. Use the BMS Tools->Upgrade Battery menu to install this update, once BMS version 1.5.1 is running.
  • If you are using a MultiGrid (AS4777 approved) device, ensure you have followed the setup instructions in the separate FAQ item about MultiGrid installation to ensure DRM is turned off off and that the wiring of AC neutrals is appropriate.  Either of these issues will stop the MultiGrid working (if not addressed).

 

Once all system elements are upgraded to the required versions, follow these instructions:

 

1) Install and configure ESS for use with ZCell systems [ For On-Grid systems only - this step not required for off-grid installations ]

 

Download and work through the annotated screen shots provided at this link to see how to set up and configure the ESS Assistant in your MultiGrid inverter/charger with settings appropriate to operate with ZCell systems.

 

It is important to be careful with loading the voltage settings noted in the attached guide, and in particular please load the correct voltages into the Charger tab after loading and configuring the ESS assistant. 

 

This will result in an operational ESS system, but for optimal results, please proceed to the next step and enable DVCC.

 

2) Enable the Victron DVCC mode [ New in CCGX version 2.12 and Firmware 424 and above ]

 

The Dynamic Voltage and Charge Current mode is designed for 'smart' battery systems that communicate via CANBus from a BMS to the CCGX. 

 

DVCC is appropriate for use with On-Grid ESS and with Off-Grid (non ESS) Victron Energy systems.

 

DVCC enables the systemwide dynamic control of current and voltage limits. It is  a major chnage in how the Victron Energy system operates. The charging cycle for batteries is no longer based on the old 'lead acid' notion of initial/bulk/absorption phases. Instead, the charging control systems enage (and switch between)  Constant Current (CC) and Constant Voltage (CV) target modes, as DC bus conditions change. The DVCC control mode is ideally suited to the operation of smart batteries with near-linear charge/discharge characteristics such as the Redflow ZCell.

 

Note: Victron Energy CANBus based MPPT solarchargers don't yet support DVCC

 

With those pre-requisites undertaken, turning DVCC on is easy: 

 

  • In the CCGX Setup -> System Settings menu, turn on DVCC
  • Then turn off SVS (This option will appear directly under the DVCC item when you enable DVCC). 

 

DVCC and SVS setup 

 

 

Note: SVS is 'shared voltage sense' - an improvement to the way the Victron system senses bus voltage - but one which is (at the time of writing) incompatible with the ZCell battery - hence ... just turn it off. If SVS isn't turned off, the system will 'hunt' in terms of target voltage and current over time and will be unable to smoothly bring a ZCell through its post-maintenance pre-charge phase to start to charge it up again. It is likely that SVS will be supported for use with ZCell systems in a later release of the Victron software/firmware.

 

 

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