Retrofit Early-Warning Module for Battery Fire Risk in Existing Electric Two-Wheelers: A Conceptual Framework

The rapid adoption of electric two-wheelers (E2Ws) in India has been accompanied by recurring lithium-ion battery fire incidents, several fatal, particularly where charging occurs within domestic premises.Amendments to the AIS-156 safety standard now mandate thermal-propagation prevention and a thermal-event warning, but only for newly certified battery packs leaving the substantial existing E2W fleet, much of it reliant on passive cooling, without such protection.Battery-safety research has separately established that thermal runaway is preceded by measurable precursor signals gas venting, abnormal casing temperature and pressure rise, and late-stage voltage irregularities detectable minutes ahead of failure under laboratory conditions, with gas-based indicators emerging earliest.However, such sensing principles remain confined to OEM-level integration and are increasingly patented at the battery-pack design stage; no low-cost, vehiclemountable retrofit device translates them into an earlywarning solution for vehicles already on the road, and commercial alarm accessories for E2Ws address theft rather than battery safety.This paper does not propose a new sensing principle; it presents the conceptual design of a retrofit earlywarning module that repackages established gas, thermal, and current-sensing techniques into a low-cost, aftermarket form factor to alert riders of an emerging thermal event.The system is intended to extend laboratory-validated precursor-detection principles to the existing E2W fleet, offering a low-cost pathway toward improved safety awareness without claiming to eliminate battery fire risk entirely.