A Kia dealer might dismiss battery health values not read by the Kia Diagnostic Unit (KDU). Some dealers believe they can improve the Guess-o-Meter (GoM) with BMS updates. However, these updates can reset the BMS to default values, requiring several cycles for accurate data. This can lead to an inflated State of Health (SOH) reading above 70%, potentially masking a battery issue.
To ensure an accurate reading, request the dealer follow the procedure outlined in PS 548. This document emphasizes reading BMS data before applying any updates to avoid incorrect SOH readings. Highlight the crucial steps in the document to ensure the dealer understands the correct procedure. A reading below 70% should trigger a dealer report to Kia Corporate, potentially leading to a battery replacement.
Alternatively, calculate the SOH yourself. After a full charge, reset the mi/kWh reading (it will display “–“). Note the mileage and battery percentage (if not 100%). At the next charge, note the mileage and percentage before charging and record the mi/kWh.
Calculate the SOH using this formula:
- kWh Consumed: (Difference in Mileage) / (mi/kWh)
- 100% Capacity: (kWh Consumed) / (Difference in Battery Percentage x 0.01)
- SOH: (100% Capacity) / (Nominal Battery Capacity) x 100
Use the appropriate nominal battery capacity for your vehicle (e.g., 27, 30, 39.2, or 64 kWh). This calculation method has been tested against professional diagnostic tools and provides comparable results. Ensuring a proper SOH reading is crucial for maintaining your Kia’s battery health and performance.
