# Protocol Description

This file documents the protocol visible from the released CSV. Hardware-level details marked `TODO` should be completed from the acquisition repository or lab notebook before public upload.

## Cell

- Format: 18650 cylindrical lithium-ion cell
- Manufacturer/family: LG 18650 NMC family
- Nominal capacity used for current-normalized experiments: 3.5 Ah
- Chemistry description: NMC-based cathode, graphite-based anode assumed from cell family
- Cell ID in processed experiments: `local_cell_001`

TODO before publication:

- Exact commercial part number, if confirmed.
- Initial measured capacity and date of receipt.
- Prior life / second-life condition, if known.
- Datasheet source used for nominal capacity.

## Test Overview

The file contains one main protocol:

```text
real_udds_leq3v4_with_rpt
```

The protocol includes:

- UDDS-style dynamic operation
- Full CC/CV charging
- Reference charge
- Reference discharge
- Reference-discharge label windows
- Rest periods before/after cycling and reference tests

## Current Convention

The processed dataset uses:

```text
positive current = discharge
negative current = charge
```

This must be stated clearly because many public battery datasets use the opposite sign convention.

## Reference Tests And SOH

SOH and capacity labels are sparse and are primarily associated with reference-discharge-related rows. For transfer experiments, the local reference capacity is inferred from the 100% SOH state in the file, approximately 3.219 Ah.

Recommended SOH definition:

```text
SOH_percent = measured_capacity_ah / reference_capacity_ah * 100
```

where `reference_capacity_ah` should be explicitly stated in any paper using the dataset.

## Acquisition System

TODO before publication:

- Cycler or load model
- Voltage measurement resolution and accuracy
- Current measurement resolution and accuracy
- Temperature sensor type and placement
- Sampling configuration
- Environmental chamber or ambient lab condition
- Data logger / controller software version

If the later pack dataset uses SPC58EC, BMS63, SPI, and AEK MCU acquisition, document it separately because it is a different acquisition system and a different scientific contribution.

## Recommended Preprocessing Notes

Users should:

- Parse `datetime` as UTC.
- Sort chronologically.
- Treat duplicate timestamps explicitly.
- Check time gaps before sequence modeling.
- Avoid using `SOH` or `capacity_ah` as input features when the target is SOH prediction.
- Use `SOH` and `capacity_ah` only as labels or diagnostic references.
- Preserve current sign convention.

