Gas detection

Example

Use in Lemonergy

Connect mechanisms with appropriate test evidence.

This is a reference concept. No executable Lemonergy block has been verified for this term.

Connected concepts

Related concepts from the knowledge graph. Connections show context, not cause and effect. Hover or focus a linked term for its definition.

Battery management system

The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.

Early thermal-runaway detection

Spotting a failing cell before it runs away, from the signals that precede heat: a voltage drop or abnormal self-discharge from an internal short, then vent gas, pressure and swelling, then a rising rate of temperature increase. Vehicle rules demand a warning to occupants at least five minutes before a hazard reaches the cabin, so detection cannot wait for heat.

Fire suppression

Systems that cool or smother a battery fire: water mist and flooding for cooling, inert gas or aerosol for enclosed storage containers. Because the cell makes its own oxygen, suppression mainly limits spread and cools neighbours rather than extinguishing the failing cell.

Off-gas

The mixture released when a cell vents: electrolyte vapour, hydrogen, carbon monoxide, carbon dioxide and hydrocarbons, with hydrogen fluoride. It is flammable and toxic, and gas sensors detect it before smoke or heat in a storage container.

Venting

The controlled release of gas and vapour from a cell whose internal pressure has risen too far, through a vent designed to open before the case bursts. The vented gas is flammable and toxic, so packs route it away from occupants.

References & further reading

Further reading on this topic

These sources provide broader context; they are not presented as citations for every statement in this entry.

1. Thermal runaway mechanism of lithium ion battery for electric vehicles: A review

   Xuning Feng et al. · Energy Storage Materials · 2018

   Topic background · Electrical, mechanical and thermal abuse; thermal-runaway mechanisms and propagation.