This is a step-by-step guide to connecting a set of Redflow ZCell/ZBM2 batteries to an energy system using Victron Energy components.
This is a differences guide only!
It assumes you already know how to set up a working Victron Energy system (and how to set up and use ESS if it is an on-grid system).
The installer must is already be trained in the design and installation of Victron Energy based systems. If this is not the case, they need to undertake Victron Energy system training first.
Redflow is not a Victron Energy training provider - Redflow's own training is differences training (as is this installation guide). It assumes you, as an installer, already know how to install a Victron based energy system based around a smart (e.g. Lithium and Lithium BMS) based battery - or at the very least using a conventional Lead-Acid battery.
- The ZCell physical installation has been done in accordance with Redflow guidelines and training
- The ZCell BMS has been physically installed and powered up (see the BMS guide section for physical BMS interface details)
- The BMS is successfully communicating with the ZCell cluster using CANbus [ see this article for instructions on how to do this ]
- For an on-grid system - that the system has been designed, wired and intended to be configured in accordance with the Victron Energy ESS Design and Installation Manual
- That all firmware and software elements have upgraded to at least the minimum required versions (as noted below) and preferably to the latest production releases of all components concerned
It is strongly recommended to upgrade to the latest production releases and to re-check and further update these system components at regular intervals. These system elements and their functionality and feature sets are regularly improved over time by both Redflow and Victron based on learnings obtained and issues resolved in the field.
Absolute minimum recommended versions for new installations are (as at March 2019):
- CCGX / Venus GX needs to be running version 2.22 or later (normally set the CCGX to auto-update to new releases)
- MultiGrid/MultiPlus/Quattro systems need to be upgraded to Firmware 433 as the absolute minimum using VE.Flash.
- MultiGrid/MultiPlus/Quattro systems need to be running the latest ESS Assistant (or at the very least, version of 016C - released on 4th July 2018) and preferably the latest release. See https://www.victronenergy.com/live/assistants:how_to_update_an_assistant
- VE.Direct MPPT solarcharger units (if used) need to the latest released firmware.
- The Redflow BMS needs to be running the latest release (or at least 1.6.0). Use the Tools->Upgrade BMS page while the BMS is Internet-connected to ensure you are running the latest production release.
- ZCell batteries should be running battery firmware 32.18.00 or later. The latest battery firmware is carried within the BMS software update package and can be upgraded using the Tools->Upgrade Battery BMS menu item.
Once all system elements are upgraded, follow these instructions:
Install and configure ESS for use with ZCell systems (on-grid installations only)
Note: ESS is not required and generally not installed in off-grid installations.
Use VE.Configure to load in the "ESS Assistant" to your Multi/Quattro just as you would for any other ESS based Victron installation, in accordance with:
Download and work through the annotated screen shots in the attachment to this article. This shows a typical set of screen shots as one works through the VE.Configure pages to load and configure the ESS Assistant into a Multi or Quattro.
It is important to load these voltage and other assistant settings as noted in the attached guide.
If these are not set correcting the system may not operate correctly.
- These screen shots are from an earlier ESS Assistant version (sorry - will be updated later). The latest versions require you to enter the battery capacity in Amp-hours into the Assistant as well. Use 200Ah per ZCell - e.g. for a (say) 4 battery system, use 4 x 200 = 800 Ah.
- The voltages in the cutoff table are non-critical as long as they are less than 42V.
- The sustain voltage is non-critical as long as it is 40V or less (40V works fine too).
- The settings for downstream PV should be 'as appropriate' for your system.
- There is no need to adjust other charger voltages or battery type in VEConfigure after loading the assistant, as the DVCC function overrides all the other firmware voltage/current settings in practice once it is enabled and active using CANBus
- As for all ESS based systems, the ESS Assistant must be loaded into all Multi/Quattro units in a multi-unit system.
Enable the Victron DVCC mode (for all ZCell systems)
The Dynamic Voltage and Charge Current mode is designed for 'smart' battery systems that communicate via CANBus from a BMS to the CCGX (such as the Redflow BMS and ZCell units)
DVCC is appropriate for and recommended for use with both On-Grid ESS and Off-Grid (non ESS) Victron Energy systems.
DVCC enables the system-wide dynamic control of current and voltage limits based on BMS information. It is a major enhancement in how Victron Energy systems operate.
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 that on-screen displays when DVCC is operational show 'Absorption' when in CV mode, and 'Bulk' when in CC mode.
Note: Older model Victron Energy based MPPT solarchargers (that don't have VE.Direct connection paths) do not support DVCC. All the VE.Direct based units do support it. Only use VE.Direct MPPT models for new installations.
With those pre-requisites undertaken, and with CANBus communications from the BMS to the CCGX screen already operating (as per other knowledge base articles), turning DVCC on is easy:
- In the CCGX Setup -> System Settings menu, turn on DVCC (as per the screen shot below)
- Then under the DVCC switch, please turn off SVS (This option will appear directly under the DVCC item when you enable DVCC):
Note: SVS is 'shared voltage sense' - an intended improvement to the way the Victron Energy system senses bus voltage. However, SVS is (at the time of writing) incompatible with the ZCell battery and BMS operating cycle and- 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. Leaving SVS on may also lead to system voltage surges during substantial changes in bus operating conditions over time, with the potential for intermittent ZCell protective shutdown/restart cycles occurring as a result.
Other Post-Installation Settings to adjust in a Redflow installation
Note that for correct system operation, the Settings->ESS menu 'Min SoC' value must be set to 0% in single-ZCell systems.
This value can, if desired, be set to a non-zero value (but generally not above 50% in multi-ZCell systems). This is to ensure that it is possible for the discharge/maintenance cycle required by the ZCell to operate properly.
In a single ZCell system where MinSoC is desired to be non-zero, consider instead the use of the CCGX 'Scheduled Charging' feature (a sub-menu under the ESS Menu) to perform a baseline charge once a day at a time that still allows for the battery to discharge for maintenance successfully when required.
ESS Operating Mode
It is important to ensure the Settings->ESS Menu 'Operating Mode' is set to 'Optimised (Without BatteryLife)' and not set to 'Optimised (With BatteryLife)'
The Victron Energy 'BatteryLife' feature is incompatible with the need to fully discharge the system periodically in a single ZCell environment.
In a multiple ZCell installation, BatteryLife might in principle be able to be used, but Redflow recommends that BatteryLife is disabled in all Redflow installations for various reasons reasons, including to ensure that battery maintenance cycles can be performed efficiently.
Quattro/Multi 'Low Battery' Alarm
You should disable the 'Low Battery' alarm for your Quattro/Multi environment to avoid swamping your CCGC display with spurious Low Battery alarm notifications each time your system is performing battery maintenance.
You can find this setting by selecting your Multi/Quattro on the CCGX menu and navigating to the 'Alarm Setup' sub-menu, and then setting the first alarm in the list, 'Low Battery', to Disabled
That the CCGX picks up NTP based (Internet-synchronised) time automatically, but you do have to tell it which timezone it is physically installed into.The system timezone should be set correctly under the Settings->Date & Time menu, to obtain accurate (local time) based logging information and so the time shown on the on-screen CCGX display is correct.
In case of problems
First, do check to make sure you have made all the setting changes noted above!
Next, you can try upgrading firmware (including in the Multi/Quattro and in the BMS) to the latest released versions first. A very wide variety of issues are dealt with and handled in improved ways in newer software releases.
Also do check the diagnostic advice under the 'Victron Energy Troubleshooting' section of this Guide Centre - as a number of common operational issues and their solutions are covered there.