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Victron & Redflow ZBM2 / ZCell

ZCell is a packaged bundle of the Redflow ZBM2 battery inside an external-rated enclosure, supplied with the Redflow CANbus BMS.

The Redflow ZBM2 battery is a 48V 10kWh DC Zinc-Bromide hybrid flow battery that is installed in parallel-wired DC clusters. It is the worlds smallest commercial flow battery. It uses the Redflow CANbus BMS as the control and communications interface for the battery system.

An overview of the technical specifications of this battery are provided here:

Important information about installing and configuring ZBM2 systems with Victron Energy products is provided here:

Compatible Victron products

  • All 48V Multis and Quattros.
  • All 48V solar chargers
  • A Color Control GX or Venus GX running DVCC and using the CANBus interface. Interfacing using MODBUS-TCP is also possible (but deprecated for most situations in favour of CANBus).

ZBM2 / ZCell Characteristics

  • Designed to be charged up to 100% SOC and discharged right down to 0% SOC (and zero volts) regularly with no damage and no loss of output capacity over the battery lifetime
  • You should configure the disconnect voltage on a Multi or Quattro right down to the minimum allowed to get all the energy out of each discharge cycle - the ZBM2 cannot be damaged by being totally empty for as long as desired.
  • Set any SoC MinSOC limit in ESS to 0% to use the full energy in the battery (single battery setups). Higher values of MinSoC can be used in multiple-ZCell installations if desired
  • Use the ESS mode “Optimised (without BatteryLife)” to allow full-depth discharge of the battery regularly.
  • Clusters of multiple ZBM2 batteries are automatically controlled using the Redflow BMS to orchestrate their discharge cycles and maintenance cycles for maximum energy availability and maximum operating efficiency and effectiveness.

Color Control GX / Venus GX Interface

The Redflow ZCell BMS supports the same CAN-bus protocol connection to the Color Control GX that is used with many Lithium Battery BMS systems.

The best way to interface from a Redflow battery system to the CCGX is to use a canbus connection on the ZCell BMS and to follow the Color Control GX canbus interface procedure as for any other CAN-bus BMS based battery.

The Distributed Voltage and Current Control (DVCC) feature provides excellent outcomes and provides very tightly integrated operation and control. The use of DVCC is normal (and highly recommended) for all new ZCell/ZBM2 installations.

A deprecated MODBUS-TCP interfacing approach is on the ZCell website. This can update the SOC on the Color Control GX using MODBUS-TCP over ethernet instead of using CAN-bus as the interface mechanism. For installations that are not using DVCC, you should limit the maximum charging voltage for all charging elements in the system to 56V.

This page on the ZCell web site explains how to interface and configure a system to use ESS (if needed) and to activate DVCC:

Important Caveats:

  1. At present when DVCC is turned on for Redflow ZBM2 based installations, it is required to turn the SVS (Shared Voltage Sense) function OFF. The SVS option appears under the DVCC item after DVCC is turned on. This limitation may be removed in a future DVCC release.
  2. For successful operation on-grid of Redflow ZBM2 systems with the Victron Energy MultiGrid 48 product series (with AS4777 grid approval) in Australia, the minimum MultiGrid-I vebus firmware revision required is version 424 and the minimum for MultiGrid-II models is firmware version 425. Please read this Redflow FAQ page about MultiGrid interfacing for further information about how to install a MultiGrid product onto a grid connection in Australia.
  3. For successful black-start using VE.Direct MPPT units as the sole startup energy source with DVCC enabled, the VE.Direct MPPT units must be running Firmware version 1.30 or later.


battery_compatibility/redflow_zcell.txt · Last modified: 2019-01-22 10:16 (external edit)