Blackout: exposing the hidden risks of battery failure in lift passenger emergency systems

Part of the authors’ professional duties includes the regular condition and compliance auditing of 2,600 lifts across 20 diverse Client portfolios throughout the UK. Any fault or non-compliance found that represents a hazard to users or engineers is reported back to Client and Service Provider alike via Hazard and Incident (H&I) Reports. During 2023 the authors raised 573 H&I Reports, suggesting that at any one time around 20% of the portfolio demonstrated a safety or compliance issue. Further scrutiny revealed that of those H&I Reports a startling 475 (83%) related to failures of emergency battery back-up power, with 262 (46%) directly relating to autodialler emergency communication failures. This data leads to the alarming hypothesis that 18% of this portfolio’s emergency batteries will be ineffective at any given time, and 10% of autodiallers will be entirely inoperative during a mains power failure. This raises the frightening prospect of large numbers of lift users being potentially trapped in the dark with no means of communication. This paper conducts detailed analysis of the dataset, identify the functions negatively affected by battery failures, commenting on the potential impact to users, and explores component and system designs that both aid and hinder effective charging, monitoring and replacement of battery systems. The authors see this issue as a significant safety failing in the UK’s (and potentially the global) vertical transportation industry. We are not content with merely highlighting this issue and will be championing an industry-wide campaign to address these safety-critical failings.