If a rechargeable ELT battery has not been used, when should it be replaced or recharged?

• A. After 1 cumulative hour of total use
• B. After 10 years
• C. Immediately upon replacement of the ELT unit
• D. There is no replacement required if not used

Answer: (A)

Rechargeable ELT batteries are evaluated by how much they’ve been used, not just by calendar time. The battery should be recharged after the beacon has accumulated one hour of operation since the last recharge. If the unit hasn’t been used, there’s nothing to recharge yet. This usage-based requirement ensures the battery has enough capacity for a real emergency. Replacing after a fixed calendar period (like ten years) or only when the ELT unit itself is replaced isn’t how rechargeable ELT batteries are managed, and assuming no replacement is needed if unused isn’t accurate for ongoing readiness.