Which statement about EFB battery requirements is accurate?

• A. Minimum battery level is 50 percent plus 10 percent for each hour of flight
• B. Battery must always be 100 percent
• C. Battery usage is unrestricted
• D. Batteries must be removed before flight

Answer: (A)

Power availability for the EFB is about ensuring the device stays powered for the entire flight and any potential contingencies. The minimum battery level rule—50 percent plus 10 percent for each hour of flight—provides a simple, scalable way to plan power for the expected duration and a cushion for delays or extra tasks. For example, a one-hour flight requires at least 60% charge before departure, a two-hour flight at least 70%, and a four-hour flight at least 90% (50% + 4×10%). If the trip could stretch to five hours or more, you’d aim for full capacity or arrange external power, so you’re not caught short. This approach reflects prudent power management; other statements aren’t practical in the cockpit—having to stay at 100% all the time ignores normal usage and wear, power isn’t unrestricted during flight, and removing batteries would defeat the EFB’s purpose.