Preparing an iPhone for power outages

We just survived Hurricane Sandy here in the Washington DC area. We were fortunate that we did not get more damage in this area. The Derecho in June seems to have prepared the area. However, I wanted to be prepared this time and I wanted to make sure I could use my iPhone if the power went out.

I have a few devices available to me: I was going to use an iPhone solely for emergency calls. I prepared a 5th gen iPod Touch for listening to audio books and reading social media while my WiFi stayed up. I saved the iPad and my Android devices for entertainment. I still also have a landline, but you never know if you will have to leave your house in a disaster and then you’ll really want your smartphone with you.

So how can you prepare an iPhone for emergency calling usage? (Note that while I’ll be discussing iPhones, this applies to Android phones too, but the setting names will be different.)

The primary concern I had was battery life. I’m currently using an iPhone 4S and it has a reputation for not having a long lasting battery. However, I was determined to make it last and preferably for several days in case the power were to go out for that long.

I prepared my iPhone at 3:30PM on Monday when the storm started picking up. On 3:30PM Tuesday, the worst was over. I had made one 6 minute phone call to change an upcoming hotel reservation. In 24 hours, the battery had only gone from 100% to 95%. At that rate, the iPhone would last for approximately 20 days.

Full battery

Here’s the steps I took to prolong my battery life (all of these are found in the Settings app):

  • Location Services: Off. You won’t be able to use Find My Phone, but that’s not really your top priority in an emergency since you’ll likely keep a tight leash on your phone. This relies on GPS which is a big power drain for phones.
  • Wi-Fi: Off. WiFi takes less power than GPS, but it still is a drain especially if you have background services like iCloud, which do work even when you’re not using an app. Use another device for WiFi if you need it. Better yet, get a battery-powered AM/FM radio to get news during emergencies.
  • Brightness: All the way to the left. Screens use a lot of power, but you save power by setting it to the dimmest setting.
  • General > Network > Cellular Data: Off. 2G, 3G and LTE all utilize power, with the newer technologies using the most. If you need to leave the house, then I’d turn this on when you need it.
  • General > Usage > Battery Percentage: On. This provides a nice percentage next to the battery icon to let you know how much battery you have left.
  • General > Bluetooth: Off. Yes, bluetooth uses power too.
  • General > Auto-Lock: 1 Minute. For the most power savings, turn off the screen manually when you’re done using your phone. However, this will make sure you don’t leave it on for more than a minute.

Why not just enable Airplane Mode, you say? It turns off all of these, but it also turns off cellular voice, which defeats the purpose of having an emergency smart phone.