The four stages of battery failure are:
- Abuse (either thermal, electrical or mechanical)
- Off-gassing (vapor released through built-in vents)
- Smoke generation (a sign of thermal runaway)
- Fire ignition (leading to propagation)
Stages 1 and 2 are the ideal times to act. If Stage 3 is reached, failure is imminent and your efforts should shift to operational safety and containment.
Green indicates the de-escalation stage, where you can still take action to mitigate the event. Red indicates that the situation has escalated and a containment strategy is required.