DATA DICTIONARY

Description:
Battery cycling test data containing rest, constant-current (CC), constant-voltage (CV) and dynamic profile steps.
The dataset includes electrical, thermal, and timing information recorded during testing.

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COLUMN DEFINITIONS AND NOTES
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Cycle Index
Type: Integer
Units: None
Description:
Sequential index of the charge–discharge cycle.
Notes:
- Increments after based on the .

Step Index
Type: Integer
Units: None
Description:
Index of the step within a given cycle.
Notes:
- Used to group different operations (rest, charge, discharge) inside one cycle.

Step Type
Type: String
Units: None
Description:
Type of operation being executed.
Examples:
- Rest: No current applied.
- CC DChg: Constant-current discharge.
Notes:
- Naming conventions depend on the battery tester software.

Time
Type: String
Units: hh:mm:ss
Description:
Elapsed time since the beginning of the current step.
Notes:
- Resets to 00:00:00 at the start of each new step.

Total Time
Type: String
Units: hh:mm:ss
Description:
Elapsed time since the start of the entire test.
Notes:
- Monotonically increasing throughout the experiment.

Current (mA)
Type: Float
Units: mA
Description:
Applied current to the cell.
Notes:
- Positive current indicates CHARGING.
- Negative current indicates DISCHARGING.
- Zero current corresponds to rest steps.

Voltage (V)
Type: Float
Units: V
Description:
Measured terminal voltage of the battery cell.
Notes:
- Drops during discharge and rises during charge.

Capacity (Ah)
Type: Float
Units: Ah
Description:
Cumulative transferred electric charge.
Notes:
- Typically resets at the beginning of a new step or cycle.
- Increases in magnitude during both charge and discharge.

Energy (Wh)
Type: Float
Units: Wh
Description:
Cumulative transferred energy.
Notes:
- Computed by integrating power over time.
- Typically resets at step or cycle boundaries.

Date
Type: Datetime String
Units: YYYY-MM-DD HH:MM:SS
Description:
Absolute timestamp of the measurement.
Notes:
- Useful for synchronization with external sensors or logs.

Power (W)
Type: Float
Units: W
Description:
Instantaneous electrical power.
Notes:
- Computed as Voltage × Current.
- Positive during charging.
- Negative during discharging.

V1 (V)
Type: Float
Units: V
Description:
Auxiliary voltage measurement channel.
Notes:
- Often unused or near zero if no auxiliary sensor is connected.

T1 (°C)
Type: Float
Units: °C
Description:
Temperature measured by auxiliary sensor channel 1.
Notes:
- Typically represents surface or ambient cell temperature.
- Small fluctuations during rest are normal.

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GENERAL NOTES
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- Time resolution may vary by step (e.g., 1 s during rest, 5 s during CC steps).
- Recommended to convert current from mA to A for physics-based models.