WatchMonPlus WM5 (FAQ) Frequently Asked Questions

For other supervisors please refer to Watchmon4, WatchMon1 or PacMon guides for their relevant procedures.


WatchmonPlus combines the supervisor and cell management into one compact single device.

New Features: 

  • Combines supervisor with on-board cell management to offer "All in One" solution.
  • Less wires: no daisy-chain network cables between cell monitors.
  • Enable second life use of existing balancing connectors in OEM packs like Tesla, Nissan Leaf, Chevy Volt, etc. that use "shared" wires between series.
  • Auto-Level (balancing) function at 500mA with activity LED on each cell.
  • Capable of 6 Ah/day balancing adjustment for each cell .
  • 3 external temperature sensors.
  • 5 LED's showing operating status and battery SoC% (state of charge).
  • For high-voltage battery systems, supervisor can be configured as a slave  (Multi-Mon - due out October/November 2019).

Adoption of Supervisor Features: 

  • Same supervisor functionality as WatchMon4.
  • Link to ShuntMon with 500A or 1000A power rating.
  • Ease to use pluggable screw-terminal connectors.
  • Opto-Insulated CAN bus to remote charger/inverter equipment.
  • Opto-Insulated RS485 (future feature for modbus).
  • Configurable 2 inputs and 2 outputs (i.e. remote circuit breaker trip, contactor or fan).
  • Additional inputs/outputs can be accessed using same Expansion Board (same as Watchmon4).

Installation procedures

Initial Communication

We always start by setting up the software and communication to the device.  This occurs with just the WatchMon connected via the provided USB cable.

Installation steps for the Watchmon Toolkit software

Installing USB drivers for Watchmon supervisor

Upgrading the Firmware on the Watchmon supervisor 

Running the Wizard setup to define your system

Multiple Cell Monitors or "multi string" configuration adding batteries in parallel to the same WatchMon supervisor

Multi-string is still possible but we are limited by the number of cell monitors in the on-board system.  We do have the ability to run multiple WatchMonPlus in master/slave mode (Multi-Mon - due out October/November 2019) but this will not be available in the initial release.

Wiring up 

The next step is to wire up the batteries to our system.  

Before wiring up please refer to Design Considerations WatchMonPlus

Please note that the WatchMonPlus was designed for shared balancing cables such as those you would find in 18650 PCB cell holders and repurposed cells (salvaged EV)

WARNING:  Always disconnect the batteries from the WatchMon when re-configuring or working on the batteries and ensure that it is wired up correctly.  Test the wiring by using the TestMon before plugging into the WatchMon.  Failure to follow this Warning may cause damage to the WatchMon and/or batteries.

Depending on your configuration, add jumpers to the wiring pins as required.

An example of wiring up to 18650 PCB Cell holders is in this Video. Many of the steps are similar with repurposed cells (salvaged EV) with the balancing wires hooked up to pluggable connectors according to how many you are using in series.

Example wiring Tesla modules to TestMon

Troubleshooting TestMon

Verifying setup using Software

Now that your batteries are connected to the WatchMonPlus we follow the same steps as we did with WatchMon4 to check for a circuit and ensure setup, created using the wizard, matches what you have wired up. 

How to connect the SOC% Sensor to Watchmon supervisor

Connecting Wifi

At this point, or later if you prefer, you can setup wifi.  Just remember that wifi is 'read only' at present so you cannot change the configuration if connected this way.

Connecting to WatchMon4 via Wifi

Inverters & chargers

Inverters and chargers can be controlled using CANbus if we have written an interface to it.  This generally involves sharing the targets set in the WatchMon Toolkit with the inverter so that it can utilise them, and letting the inverter know the current state of the batteries.  Some inverters are more sophisticated than others therefore, what is shared depends on the inverter/charger.

How to control a SMA Sunny Island inverter/charger with a WatchMon

How to control a SolaX hybrid inverter/charger with a WatchMon

How to control a Victron Color Control GX with a WatchMon

How to control a Victron Venus GX with a WatchMon

How to control a Redback smart hybrid inverter/charger with a WatchMon

How to control a Brusa NLG5 charger with a WatchMon

How to control a Brusa NLG6 charger with a WatchMon

How to control a TC/Elcon charger with a WatchMon

How to control a Eltek Flatpack2 charger with WatchMon

How to control a EnPower charger with a WatchMon

Connecting external Fans/Contactors and Circuit Breakers

Electronic Auxileries - Schneider Electric - Double Pole Circuit Breaker 125A 15kA

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

How to connect the WatchMon4 to the Schneider Electric Circuit Breaker

Schneider Tripping Unit - product page

Schneider Circuit Breaker 125a 15ka - product page

How to Connect a Fan to On-Board Relay Expansion Board

How to Connect a Fan to On-Board Output WatchMon4

How to Connect a Fan to Expansion Board

How to Connect a Contactor to On-board Output WatchMon4

How to Connect a Positive Switch Latching Contactor to Expansion Board


Understanding Watchmon operating state LED indicator

Where do I find a pincode?

Troubleshooting pincode

How to modify the Technician pincode

Troubleshooting wifi

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