Charge Cycle Management
Lithium batteries age rapidly if they are kept above 70% 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:
- charge it
- stop charging when it is full
- 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:
- to start, TAO BMS lets the chargers do their job until the battery is fully charged (100% SOC has defined in the SOC parameters)
- then the “Relays to disable charge” are activated (and / or a CANbus message is sent to the chargers to stop them – needs TAO monitor and CANbus compatible chargers)
- the charger stay disabled until the battery is discharged to the set “Low SOC” value (35% in the example above), then TAO BMS enables the chargers (relays and/or CANbus)
- the chargers stay enabled until the charge of the battery reaches the set “High SOC” value (80% in the example above)… go to step 2…
- when the number of days since the last full charge reaches the set “Time between full charges” value (30 days in the example above)… go to 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 at the lowest range)
- 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 CANbus (we will provide the CANbus command to match your equipment if not yet done)