Battery health of electric and hybrid cars

Where: Remote sessions › Diagnosis › Service functions › “v2 procedures” channel

Important: Read only: these procedures do not act on the high-voltage system. Do not touch orange cables or connectors or open the battery; that work is only for staff trained in high voltage.

1. Tick “Electric and hybrid only” and look for the “High-voltage battery health” procedure of your model (Kia Soul EV, e-Niro and Hyundai Kona, MG ZS EV and MG5, Chevrolet Bolt and Volt, Fiat e-Doblò, VW e-up!, smart ED…). For any hybrid with OBD, use “Hybrid and electric battery via generic OBD”.
2. Car stationary, parking brake on and ignition on or “ready”. Launch the procedure and confirm the high-voltage warning shown at the start.
3. When it finishes you see the “Battery health” report: health (SOH or capacity), state of charge, cell voltages with the lowest, the highest and the spread, temperatures and energy counters. You can print it.
4. If you issue the pre-purchase report with the same unit within 24 hours before or after, the high-voltage battery goes into that report, signed.

• There is no verdict: no manufacturer publishes health or imbalance limits in open sources. Compare with other cars of the same model and, if in doubt, ask the dealer for a capacity test.
• The on-board charger is read with the car plugged in and charging: do not unplug the cable while reading.
• They are all beta: the data comes from open projects (OVMS, MIT license) and still needs tests on real cars. Renault Zoe, BMW i3, Hyundai Ioniq 5, Kia EV6 and Toyota bZ4X have no usable open source: they need the manufacturer's license.
• On UK and EU MG ZS EVs, read with the ignition on: if the car started charging locked and asleep, the gateway does not answer.

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