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New feature: Charge Cycle Management

Lithium batteries age rapidly if they are kept above 80% SOC (state of charge) most of the time.   TAO BMS has a new feature to manage the charge cycles and extend battery life.  Just set it up and forget about it.

The best way to use a lithium battery and keep it healthy:

  1. charge it
  2. stop charging when it is full
  3. do not start charging again until the the battery is close to empty.

In addition a lithium battery does not need a full (100%) charge every time


Easy to say, but none of the chargers we have onboard are designed to do that.  They charge to 100% SOC, then switch to “Float”…. and start charging again the next day until 100% SOC.  That was good for lead-acid / AGM batteries, but that will shorten the life of your new lithium battery.

TAO BMS has a new feature to manage the charge cycle and do what is best for the battery.  Just a few parameters to set and you are good to go (the current shunt option is required to enable that function).

How it works:

  1. to start, TAO BMS lets the chargers do their job until the battery is fully charged (100% SOC has defined in the SOC parameters)
  2. then the “Relays to disable charge” are activated (and / or a CAN message is sent to the chargers to stop them – needs TAO monitor and CAN compatible chargers)
  3. the chargers stays disabled until the battery is discharged to the set “Low SOC” value (35% in the example above) – at that point the TAO BMS enables the chargers (relays and/or CAN)
  4. the chargers stay enabled until the charge of the battery reaches the set “High SOC” value (80% in the example above)… then it keeps going steps 2, 3 and 4 until condition for step 5 is true
  5. when the number of days since the last full charge reaches the set “Time between full charges” value (30 days in the example above), then TAO BMS wait until a full charge is done (step 1).

This is possible because:

  • TAO BMS keeps accurate State of Charge information using self learning algorithms
  • The State of Charge relies on high precision current measure (current shunt with self ranging amplifier that has an accuracy of 5 mA)
  • TAO BMS can command up to 6 independent relays or external equipment / chargers
  • TAO BMS with the TAO Monitor option can directly command external equipment via CAN

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