Quantifying Transient Resistance Measurement Errors Driven by Data Acquisition Delay
Data acquisition delay inflates cell transient resistance measurements by capturing double-layer charging decay rather than pure ohmic voltage drops.
HPPC Test Protocol
Meaning
Laboratory procedures quantify the dynamic power capabilities of a battery across its full range of operating states. The hppc test protocol provides the data needed to map both discharge and regenerative pulse power at various depths of discharge. It serves as the industry standard for determining the internal resistance of a cell under load.
Execution Method
Successive pulses of high current are applied to the cell followed by periods of rest to allow for voltage recovery. During the hppc test protocol, the voltage drop is measured at specific intervals during and after the pulse. These values allow for the calculation of ohmic and polarization resistance.
Model Accuracy
Data from these tests inform the equivalent circuit models used in battery management systems. The hppc test protocol ensures that the software can predict how a pack will behave under sudden acceleration or braking. This predictive ability prevents the system from exceeding voltage limits during peak demand.
Testing Boundary
Results remain valid only for the specific temperature and state of health present during the measurement. Cold environments significantly increase the resistance values recorded during the hppc test protocol. Consistent environmental controls are required to produce repeatable data for comparative analysis.