EASA SIB 2020-18: Nickel-Cadmium Batteries - Risk of Capacity Reduction during Aircraft Parking and Storage

What to do

Aircraft Design Approval Holders should collaborate with battery manufacturers to evaluate their electrical system designs and parking/storage instructions for susceptibility to Ni-Cd battery capacity loss. If capacity reduction risks non-compliance with certification standards, DAHs must report to EASA. CAMOs should consult DAHs to determine if additional maintenance or checks are needed before returning aircraft to service. No specific compliance deadlines are stated.

Summary

EASA Safety Information Bulletin 2020-18 is a safety information bulletin addressing the risk of capacity reduction in Nickel-Cadmium (Ni-Cd) aircraft batteries during extended aircraft parking and storage, particularly due to the COVID-19 pandemic. It applies to all aircraft with Ni-Cd batteries that have been parked or stored, as well as Design Approval Holders (DAH) and Continuing Airworthiness Management Organisations (CAMOs). The bulletin highlights that Ni-Cd batteries self-discharge when disconnected, leading to irreversible capacity loss that may compromise battery endurance and aircraft electrical power reliability upon return to service.

What changed

EASA SIB 2020-18 introduces awareness of an electrochemical phenomenon causing progressive capacity reduction in Ni-Cd batteries during storage when disconnected from aircraft loads. It recommends that DAHs and CAMOs review their battery systems and storage procedures to assess potential safety impacts and compliance with certification requirements. This bulletin does not mandate actions but encourages voluntary review and reporting of any non-compliance or unsafe conditions.

Why it matters

This bulletin matters because Ni-Cd batteries are critical as the final power source for aircraft electrical systems, and capacity loss can lead to premature total electrical power failure if the main system fails. Operators and maintenance organizations must ensure batteries retain sufficient capacity after storage to meet certification endurance requirements, thereby safeguarding safe aircraft operations and preventing unexpected electrical failures.