WatchMonCore hardware guide and pin assignment

WatchMon-CORE   Replaces   WM4

Introducing the next generation of WatchMon- CORE supervisor. We have made a new model, a stronger WM4...a better 4... now shall be named " WatchMon- CORE". This revamp is taking the lessons we have learnt from WM4 and building on this proven platform introduce a few new features.
Moving forward this will be the CORE building block that additional components will link to this supervisor in the future. 

The next generation of revamped products should start to become available from April.

Store Product Link


  • BMS to suit LiFePO4, Lithium-Ion or custom chemistry
  • User configurable parameters and control logic
  • Configurable 30vdc 5A relay (i.e. remote circuit breaker trip, contactor or fan)
  • Additional inputs/outputs via Expansion Board purchased separately 
  • Compatible with all Expansion Board (series 1, 2, or 3
  • Clock with backup battery data logging of key metrics for 10 years 
  • Firmware upgrades via USB 
  • 4 stage display of State of Charge (SoC%
  • External ambient temperature sensor 
  • Easy to use pluggable screw-terminal connectors 
  • With distributed cell monitors capable of 28 Ah/day balancing adjustment for each cell 
  • Link to ShuntMon with 500A or 1000A power rating
  • Compatible with MM8

Remote Communication

  • WiFi connectivity (normal, disabled, or read only
  • CANbus Opto-Insulated to remote Charger / Inverter equipment 
  • Future feature to connecting to Cloud Portal via MQTT (secure link)


  • Easier to use layout than previous models
  • Bigger DC-DC (6W) supporting 8-65V supply
  • Cell Monitor port (aka CMU) now with its own external fully isolated communication module named "IsoMon3" that can link to LongMon, BlockMon and LeafMon
  • CMU and Shunt serial ports have a different number of pins to avoid confusion
  • New on-board Relay (30vdc 5a relay) making it easier for DIY wiring

Optional Expansion Board (series 3) details

  • 3 x Mechanical 30Vdc 5A relay outputs
  • 3 x Solid state relay SSR 65vdc 5A isolated modules outputs
  • 2 x Isolated inputs 5-65vdc sensor channel
  • 2 x ADC 0-5vdc (future development option)
  • 1 x RS485 Serial port (future development option)
  • 1 x External Addressable LED (future development option)
  • Compatible with all supervisors


  • WatchMon-CORE       Length 107 mm x Width 55 mm
  • ExpansionBoard-E3    Length 107 mm x Width 55 mm


WatchMon- CORE requires the Latest release of WatchMon Toolkit (minimum of 2.16.4)

Connecting LongMons to CMU Serial Port

  • Best to number the first cells from Negative in increasing order
  • Hi speed CMU serial  with the isolation moved to separate IsoMon3 for single cell monitors           (i.e. LongMon, BlockMon and LeafMon)
  • CMUConnect and IsoMon3 are not interchangeable 
  • WatchMon-CORE requires a IsoMon3, the use of a CMUConnect will damage the WatchMon-CORE product

Follow the commission and trouble shooting guides to install

Connecting to ShuntMon

CMU and Shunt serial ports have a different number of pins to avoid damage / confusion

Connecting to Inverter / Charger using CANbus

List of available Inverter / Charging equipment can be found from the following link

Powering WatchMon CORE supply

For High Voltage battery pack systems best to adopt a Fully isolated DC-DC to provide a supply voltage of either 12v or 24v depending on application.

  • Built-in 8v to 65v DC-DC supply (non isolated)
  • Consumes ~1.7W with WiFi enabled (typical 48v battery budget 1Ah/day)

Controlling a FAN from WatchMon-CORE Onboard Relay

  • Mechanical relay Max 30Vdc 5A
  • Labelled as Relay A
  • User defined function

Controlling a FAN from WatchMon-CORE Expansion-E3 using a Relay

  • Up to 3 Mechanical relay Max 30Vdc 5A
  • Labelled as Relay 1, 2, and 3
  • User defined function

Controlling a FAN from WatchMon-CORE Expansion-E3 using a Solid State Relay SSR

  • Up to 3 Solid State Relay SSR  3 to 65Vdc 5A (1 way disconnect)
  • Labelled as SSR 5, 6, and 7
  • User defined function(s)

Sensing Switch Signal from WatchMon-CORE Expansion-E3 using a Opto-Isolated Input

VIDEO Helicopter Preview of Product with Optional    Expansion-E3

VIDEO Overview and Unboxing

VIDEO Step by Step Supervisor Installation with LongMons

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