The tactics for fighting a lithium battery fire differ from conventional protocols, and the effectiveness of standard fire-extinguishing agents on those fires is more nuanced than a simple, “it works or doesn’t.”
With the exception of the large battery banks used on the new hybrid-electric tugs now coming into service, the batteries crews typically deal with are generally very small: mobile devices, handheld radios, EPIRBs, power tool batteries, and the like.
A small battery or battery bank (whether Li-ion or polymer) that has entered thermal runaway is very unlikely to be fully subdued with a standard ABC dry-chemical or CO2 extinguisher, since neither is capable of significantly cooling it or halting the chemical chain reaction at the root of the fire. If the fire isn't too advanced, though, they can temporarily knock down and extinguish flames on the battery’s exterior — though reignition is still likely. They remain effective, however, on surrounding materials the battery fire has ignited. This can buy the time needed to separate and move those materials away from the battery, or better still, to separate the battery from the flammable materials altogether. Getting the battery outside and onto a nonflammable surface, where it can burn itself out relatively safely, is the preferred method.
Water is very effective at containing and cooling these fires if caught early. Once the flames have been extinguished, by whatever means, submerging the battery in a steel bucket of water will keep it contained until it can be disposed of ashore. Keeping a pair of dedicated heavy-duty welding gauntlets on hand for handling a hot battery is wise, and a steel, military-style ammo can is a great alternative to a bucket for smaller batteries.
Firefighting technology hasn’t stood still. The newest industry standards for combating battery fires are F-500 Encapsulator Agent and Aqueous Vermiculite Dispersion extinguishers, both of which cool the battery and break the chemical chain reaction.
