Short Circuit
Definition
Unintended low-resistance path that allows excessive current flow, potentially causing rapid heating, component damage, and fire. Can be internal to a cell or external.
Why It Matters
- Highest current failure mode in battery systems
- Can generate extreme heat (I²R losses) very rapidly
- Requires both prevention (design) and protection (fuses, current limiters)
- Different from overload: short circuit has near-zero impedance
Common Pitfalls
- Not sizing fuses for short-circuit interrupt rating
- Relying only on contactors to interrupt short circuits
- Inadequate clearance and insulation in high-current paths
- Not considering short circuit testing in validation plan