TAO BMS kit (BMS, Monitor & shunt)
TAO BMS kit (BMS, Monitor & shunt)
TAO BMS kit (BMS, Monitor & shunt)
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TAO BMS kit (BMS, Monitor & shunt)

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More than a BMS, it is an Energy Management System!

TAO BMS is unique by the level of protection it provides and
a number of features designed to maximize battery life.

TAO BMS instillation and user manual

TAO Monitor user manual

TAO Quick setup guide.

The features that make TAO BMS unique:

  • Up to twenty ranges can be defined for cell voltage, cell temperature or battery state of charge
  • Close integration with external equipment to command their operation (6 relays and CAN messages)
  • Alarms are activated and custom commands are sent to external equipment when a range limits are reached
  • Anticipated warning before a command is sent out
  • Warning on cell voltage and temperature differential
  • Control of the charge cycle
  • Dynamic cell balancing (4 A) as soon as there is a voltage differential between cells
  • Diagnostics and simulation mode to validate proper operation of the BMS and all external equipment
  • Detailed lifetime history of events and measures to analyze cell behavior and identify slow drifts
  • Battery state of health based on individual cell resistance and measured battery capacity
  • Access battery state and historical data from the other end of the world.

The pitfalls of most BMS

A single protection range

  • usually that single range is close to the “Extreme” range

  • it will not prevent situations that speed up cell ageing

No anticipated warning

  • no time to take corrective actions before the power goes down

No relay outputs

  • the only action the BMS does is shut down the battery leaving you in the dark

Only two relay outputs

  • no possibility to connect directly to equipment with different command requirements

  • does not allow for controlling energy production, energy usage or environment (battery cooling & heating)

No CAN integration with external equipment

  • charge and discharge rates cannot be adjusted based on battery condition

No validation that commands sent to external equipment are effective

  • cannot validate the BMS is sending the right commands at the right time

  • cannot validate proper wiring of external equipment

  • cannot check if external equipment is working properly

No charge cycle management

  • best charge practices cannot be enforced (charge the battery up to a certain level then stop, and wait until the state of charge goes down to restart the charge – for example: stop charging at 80 %SOC and restart charging at 25 %SOC)

  • no possibility to command a periodic full charge

Passive cell balancing

  • energy is dissipated in the BMS, heating up it’s components and making its measures inaccurate

Balancing start on high cell voltage or large cell voltage differential (100 mV or more)

  • balancing always starts above the “optimal” range (unless the unbalance is very important)

  • balancing is active only for a short time before the chargers go to float or the BMS shuts down the battery

Low balancing current (less than 2 A)

  • if balancing starts on high cell voltage or large cell voltage differential, there is not enough current and not enough time to bring the cells back into balance

  • cells with the most charge will age faster and eventually bring the battery down

No history of measures or events

  • cannot claim battery warranty as it is impossible to show how the battery has been used

  • slow drifts are detected only when it is too late and the battery has been damaged

  • cannot identify situations that do not warrant an alarm but can damage the battery over time (example: keeping the battery or a cell above 80 %SOC or above 30 °C)

No warning on cell voltage or temperature differential

  • you will not be alerted if there is a difference in cells characteristics or a faulty cell interconnection that may damage the battery over time

You will need to get a few relays to complete your build. Please read this article on choosing the right relay.

 Proudly made in New Zealand.