During a thermal runaway event, the battery will self-discharge its entire capacity in a matter of minutes! The by-product of discharging so fast is an excessive amount of heat – and all of that energy has to go somewhere. Most commonly, this presents itself as a swelled battery – the battery will bulge from all sides.
What causes thermal runaway in lead-acid batteries?
For thermal runaway to occur in vented lead-acid batteries, very high extremes of charging current and the resultant high temperature must be present. While this document only considers thermal runaway in VRLA AGM products many of the causes are also applicable to GEL types.
Do sealed lead acid batteries have a thermal runaway effect?
The thermal runaway effect observed in sealed lead acid batteries is reviewed and reassessed as a means for understanding the effect at a more fundamental level.
What happens if a battery swells during a thermal runaway event?
During a thermal runaway event, the battery will self-discharge its entire capacity in a matter of minutes! The by-product of discharging so fast is an excessive amount of heat – and all of that energy has to go somewhere. Most commonly, this presents itself as a swelled battery – the battery will bulge from all sides.
Batteries that are reaching or have exceeded the service life are at a significantly elevated risk of Thermal Runaway. This is due to the inevitable rise of internal resistance and the deterioration of the internal materials exceeding the rated number of discharge/recharge cycles.
Lead-acid batteries, which are commonly encountered by many people, have several issues that are not well understood. One of the least understood problems is their susceptibility to thermal runaway. The Wikipedia provides a useful definition of this phenomenon.
Further, the thermal runaway shall be viewed as a general phenomenon occurring in sealed cells. The effect shall be described in considerable detail using the lead acid battery as the model. Having developed the general concept, the plan is to extend the general mechanism to show how it applies to the lithium ion