OBD
P0B29
Hybrid/EV Battery B Voltage Low
What it means
P0B29 means Hybrid/EV Battery B Voltage Low.
Check these first
- An aged battery B that is not holding charge
- A failed battery B cell
- A charging system not charging battery B
- High mileage wearing battery B
What to do next
- Read hybrid battery B voltage on a scan tool
- Check the battery B state of charge
- Test the battery B cells for a failed cell
- Check the charging system output
- Replace battery B if the cells test good but voltage stays low
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.