News | TAO BMS | Lithium batteries | Battery Management System (BMS) | Installation

A complete Energy Management System

Not only a “Battery Management System” (BMS)…

It is a comprehensive
“Energy Management System”

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

It has been designed specifically for off-grid installations: remote site, vessel, mobile home, industrial site…

A lithium (LiFePo4) cell is very sensitive to voltage and temperature.

It has a nominal voltage of 3.20 volt. There are 3 ranges of voltage to be considered:

RangeDescription
Extremeoutside of this range cells may not survive
Recommendedtypical manufacturer recommendation
Optimalfor long battery life (outside of this range cells age faster)
If your objective is to maximise battery life, you must keep it’s voltage and temperature
within the “optimal” range

TAO BMS is the only product on the market with all the features
to ensure maximum capacity and lifespan for your battery

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 analyse 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

… and it is easy to install with only 5 wires to connect to the battery
“Plug & Forget”


The TAO Performance BMS components are:

TAO BMSbase system with remote control panel to protect a 12 volt battery
BMS Shuntdevice to measure current in and out of the battery
BMS Monitortouch screen display, measures and events logger, and connectivity hub (WiFi & CAN)
BMS Extensionextensions for batteries up to 48 volts (one extension for each additional 12 volt)
BMS ConfigPC and Mac application to configure, monitor and diagnose the system

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 exemple: 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 (exemple: 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