Dealers may dismiss readings from non-KIA Diagnostic Units (KDU) when assessing electric vehicle battery health. Some dealers might attempt to improve the State of Health (SOH) by applying Battery Management System (BMS) updates, believing it enhances the Guess-o-Meter (GoM) reading. However, these updates can reset the BMS to default values, requiring multiple drive cycles to generate accurate data. This often leads to an inflated SOH reading above 70%, potentially masking underlying battery issues.
To ensure a precise SOH assessment, request your dealer adhere to the procedure outlined in PS 548 (https://www.tsbsearch.com/Kia/PS548). This document emphasizes the importance of reading BMS data before applying any updates, as doing otherwise can prevent a correct SOH reading. Highlighting the crucial steps in a copy of PS 548 can ensure the dealer follows the correct protocol. A reading below 70% should trigger a dealer report to KIA Corporate, potentially leading to battery replacement.
Alternatively, you can calculate the SOH yourself using a Car Scanner Ev capable of reading energy consumption data:
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Fully charge the vehicle and reset the mi/kWh reading (it will display “–” when reset). Record the mileage and battery percentage (if not 100%).
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At the next charge, note the mileage and battery percentage before plugging in. Also, record the mi/kWh reading.
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Calculate the kWh consumed: Subtract the initial mileage from the current mileage and divide the result by the mi/kWh reading.
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Determine the usable battery capacity: Divide the kWh consumed by the difference in battery percentages (expressed as a decimal, e.g., a 20% difference is 0.20). This provides the usable battery capacity at a 100% charge.
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Calculate the SOH: Divide the usable battery capacity by the nominal battery capacity of your Kia EV (e.g., 27, 30, 39.2, or 64 kWh) and multiply by 100. This final result is your battery’s SOH.
This calculation method has been verified against professional-grade diagnostic tools and provides comparable results, offering a reliable way to monitor your Kia EV’s battery health using a compatible car scanner EV. Regular monitoring ensures optimal performance and longevity of your electric vehicle’s battery.
