When rechargeable, batteries in an ELT must be replaced or recharged after which condition?

• A. When the ELT has been in use for more than 1 cumulative hour
• B. Every 6 months
• C. Only when the transmitter fails
• D. Never unless replaced by the manufacturer

Answer: (A)

Rechargeable ELT batteries have a limited energy supply that is sized to provide about one hour of transmitter operation. After the beacon has been used for more than one hour in total, the remaining energy may not be enough for another emergency transmission, so the battery should be recharged or replaced to guarantee readiness. This isn’t about a fixed calendar interval or about waiting for a failure; it’s about actual usage. Recharging after one hour of cumulative use keeps the ELT capable of transmitting when it’s needed most, whereas the other options would not ensure reliability.