Functional safety in a battery system doesn’t come from a single standard, it comes from picking the right one for the application and understanding how it differs from its neighbours. Automotive BMS design is governed by ISO 26262, a risk-based standard built around Automotive Safety Integrity Levels (ASIL A–D) that scale required rigour to the severity, exposure, and controllability of a hazard. Stationary and industrial battery systems more often fall under IEC 61508 (the parent functional safety standard ISO 26262 was itself derived from) or the appliance-specific IEC 60730, both of which use Safety Integrity Levels (SIL) rather than ASILs.
A separate concern, Safety of the Intended Function (SOTIF, formalised in ISO 21448), covers hazards that arise from a system behaving exactly as designed but still causing harm, increasingly relevant as BMS logic takes on more autonomous decision-making. This page sets out how these standards relate to each other before the rest of the hub goes deep on any one of them.