Watchmon4 hardware guide and pin assignment

BMS central processor for watching cell monitoring units and provides supervision functions. The WatchMon4 supervisor is able to notify remote systems (inverter/charger) of the battery state and when required trigger evasive action to prevent damage to battery pack.

Remote Communication

  • WiFi connectivity (normal, disabled, or read only)
  • Can-Bus communication port to remote systems
  • Modbus rs485 link allowing connectivity to inverters without canbus
  • optional blue-tooth connectivity (future enhancement)

Built-in input and output control

  • two (2) onboard FET outputs 4A with 8A inrush 
    • e.g. remote circuit breaker trip + fan
  • two (2) onboard input
    • e.g. circuit breaker trip sensor

Added features and I/O with Expansion board 

  • 5 Digital inputs
  • 2 Analogue inputs
  • 1 Pulse counter input
  • 8 Digital outputs  (4 FET + 4 Relay)
  • 2 Digital output PWM
  • NeoPixel LED control

    Power Input

    • Built-in 8v to 65v DC-DC supply
    • handle automotive transients
    • ESP32 more powerful than WM1
    • Data logging of key metrics for 10 years
    • Clock with backup battery
    • optional over the air (OTA) upgrades to firmware
    • upgrades firmware via USB
    • secure web encryption to allow SSL link when connecting to optional cloud portal via MQTT.
    • prevent all outputs from resetting when the processor firmware is updating (no transient on/off/on)

    BMS Module Connectivity

    • serial link to SoC% current sensor module
    • serial link to isolated CellMon modules 

    Ease of Use

    • pluggable screw terminals to simplify installation, allowing pre-made cables for both shunt and cellmons
    • relocation of onboard temperature sensor away from heat sources to have better representation of ambient conditions
    • finger guard cover clip slots, more coming soon
    • intuitive screw terminal labeling to reduce need to check documentation


    How to Connect a Circuit Breaker to Onboard Output/Input WatchMon4

    How to connect the WatchMon4 to the Schneider Electric Circuit Breaker 


    Watchmon4 - Product page 

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