Mobile Fundamentals · Inside a Phone · Lesson 5 of 5

Challenge: The Long-Haul Phone

Help a cousin prep his phone for a trip: battery, charging and restarts.

Before the trip

Your cousin Sam is flying to visit family next week, with a long layover in the middle. He has asked you to look over his iPhone before he goes.

Here's what he tells you. The phone is about two years old. When it was new, the battery easily lasted all day. Now it's nearly empty by mid-afternoon. He drives for work and usually leaves the phone charging on the dashboard, often in full sun. To protect the battery, he has started charging in short bursts, a bit here and a bit there, instead of one long charge.

He mentions a few other things too. He plans to charge at airport kiosks, his fitness app tracks his steps, and some mornings Face ID refuses to work until he types his passcode.

Start with the battery.

The airport kiosk

At the layover, Sam's battery is low again. The only charging spot near his gate is a kiosk with a row of USB ports. There are no wall outlets, and he left his battery pack at home.

He has two cables in his bag: the regular USB-C cable that came with his phone, and a charge-only cable a friend gave him. He has heard warnings about public charging ports, but his phone is at 5% and the flight is long.

He asks you for the safest way to charge here.

Landing with a dead phone

On the plane, Sam types a long message to his sister in a notes app. Before the app saves it, the battery dies and the phone switches off.

After landing he plugs his own charger into a wall outlet, and the phone starts up again. He picks it up expecting Face ID to unlock it as usual, and wonders whether his message survived.

Up the stairs

Sam's family lives on the fourth floor of an apartment building. That evening his fitness app shows a new entry, flights of stairs climbed, at about the time he walked up from the lobby.

Sam is puzzled. He knows GPS is often weak indoors, and the app knows nothing about the building. Yet it noticed he went up, floor by floor.

He wants to know which part of the phone made that possible.