Quick Look Battery Discharge Report

This Jupyter notebook provides the minimum required initial analysis for a set of battery tests performed using a Maccor battery tester. This analysis nominal current results:

• Discharge curves
• State of Charge (SOC) curves
• Discharge capacities

Requirements

File Name Structure

The file names are assumed to have the following syntax: _U<Test Item Number: 2 char>_M<Battery Model: 4 char>_D

The batteries' test item number and description will be included with the test result data frame. This allows for convenient grouping and graphing.

Maccor Output File Structure

The Maccor file structure contains many fields:

1. Rec#: Simple integer index
2. Cyc#: Each cycle consistes of a series of steps.
3. Step: Consists of charge, discharge, pause, and iterate steps.
4. TestTime: Absolute increment of time in Maccor custom format
5. StepTime: Time in each step
6. Amp-hr: The total charge into/out of the battery – depending on step
7. Watt-hr: Energy associated with charge/discharge current
8. Amps: Charge/discharge current (depends on phase)
9. Volts: Battery voltage
10. State: Letter designation of the battery state (C=charge, D=discharge)
11. ES: Unknown
12. DPt Time
13. ACImp/Ohms: AC impedance at 1 kHz
14. DCIR/Ohms; DC resistance
15. VAR1 .. VAR15: User defineable fields

Analysis Data

Data Dictionary

The notebook cleans the data and produces a data table with the following data:

• Time (minutes)
• Charge (mAh)
• Battery Voltage (V)
• Battery Model
• Unit Number

Discharge Curves

SOC Curves