Battery Cycling

Battery cycling method parameters.

Note: This method is experimental and may be subject to change.

Supported devices:

• Nexus
• EmStat4 series (EmStat4S, EmStat4X, MultiEmStat4)

This method implements CC-CV-CC Cycling with Delta-I-V and Qpass:

1. With Chronopotentiometry and Chronoamperometry to charge a cell and a Constant current followed by Constant Coltage (CC-CV).
2. With Chronopotentiometry discharge the cell at a constant current (CC).
3. Store the charge transferred during each charge and discharge step.
4. Send I-V verus time data, and the capacity per charge-discharge step (Qpass). The charge values are absolute and are converted to mAh.

The underlying methodscript is described in this application note: https://www.palmsens.com/knowledgebase-article/advanced-battery-cycling-with-methodscript/

Methods:

• render –

  Render the template with model parameters.

• to_methodscript –

  Convert to MethodSCRIPT class.

Attributes:

• id (Literal['bc']) –

  Unique method identifier.

• potential_max (int) –

  Maximum potential to charge to (units: mV).

• current_min (int) –

  Minimum current to stop the CV charge step (units: μA).

• potential_min (int) –

  Minimum potential to discharge to (units: mV).

• current_charge (int) –

  Constant current to charge with (units: μA).

• current_discharge (int) –

  Constant current to discharge with (units: μA).

• cycles (int) –

  Number of charge and discharge cycles.

• interval (int) –

  Interval time of each measurement point (units: s).

• max_time (int) –

  Maximum duration of each step (if the cut-off is not met) (units: s).

• delta_v (int) –

  Minimum potential variation required for plotting data in CC steps (units: μV).

• delta_i (int) –

  Minimum current variation reuqired for plotting data in the CV step (units: nA).

• delta_t (int) –

  Maximum time without plotting data (units: ms).

• cell_on_ocp (bool) –

  Turns cell on with the measured OCP (Nexus only).

• power_frequency (Literal[50, 60]) –

  Set the DC mains filter in Hz.

id: Literal['bc'] = 'bc'

potential_max: int = 4300

current_min: int = 5

potential_min: int = 2500

current_charge: int = 100

current_discharge: int = -100

cycles: int = Field(default=100, gt=0)

interval: int = Field(default=100, ge=0)

max_time: int = Field(default=3, ge=0)

delta_v: int = Field(default=100, gt=0)

delta_i: int = Field(default=500, gt=0)

delta_t: int = Field(default=100, ge=0)

cell_on_ocp: bool = False

power_frequency: Literal[50, 60] = 50

render() -> str

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def render(self) -> str:
    """Render the template with model parameters.

    Returns
    -------
    script : str
        Complete MethodScript code for this method.
    """
    template = env.get_template('battery_cycling.mscr')
    return template.render(model=self, timestamp=datetime.today(), version=__version__)

to_methodscript() -> MethodScript

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def to_methodscript(self) -> MethodScript:
    """Convert to MethodSCRIPT class.

    Returns
    -------
    method: MethodScript
        MethodScript class.
    """
    script = self.render()
    return MethodScript(script=script)