Managing iPhone battery life when the power goes out
I live in New Jersey, in an area hard-hit by Hurricane Sandy. Before the storm hit, my family took the traditional preparatory steps: We bought non-perishable foods, stocked up on water, took in our lawn furniture, and so on. But we also prepped our electronics for the coming storm -- chiefly, by charging up our iPads, iPhones, and laptops.
We lost power on Monday, October 29, and it wasn't restored until the evening of Sunday, November 4. Seven days without power is a long time. Of course, the biggest problems were the cold and the food spoilage. But with the Internet out, we also lost our home phone service (which uses VoIP). Nearby cellphone towers took a beating, as well; early on, our iPhones lost service completely. Eventually, AT&T and T-Mobile started pooling their resources to let customers get online, so phones linked to one provider would occasionally show carrier logos for the other.
Our phones eventually went from mostly useless to occasionally able to send SMS text messages and place heavily-distorted phone calls. But that came with a cost: Our iPhones struggled so mightily to make even those basic connections that they gobbled up battery power far faster than usual, while accomplishing far less. With limited options for recharging our iPhones, we had to do what we could to maximize battery life.
Preparing for the long haul
The first few steps were easy: We turned off Wi-Fi, so that the phones wouldn't waste energy scanning for wireless networks that weren't there. We turned off Bluetooth, too. (Both are top-level options in Settings under iOS 6.) We dialed down our Brightness settings as low as possible -- though that option was slightly harder to stick with: Our iPhones worked far better outside, and in sunlight the darkest screens were hard to read. Very dark iPhones are also subpar makeshift flashlights, which we needed with the power out.
I am fortunate enough that my job with Macworld affords me a slew of devices that can help juice iPhones in need. My collection of iPhone battery cases is huge: Before Sandy hit, I charged up five such cases. The only glitch: the ones I had work only with the iPhone 4 and 4S, so they could charge my wife's iPhone, but not my iPhone 5.
To take care of my iPhone 5, I turned to a few other options: the PowerBag Business Class Packa backpack with a built-in battery and the ability to charge devices over USB; a generic recharging device with USB, dock connector, and Micro-USB ports; and my car, thanks to a drugstore-purchased USB/cigarette-adapter plug. We also had three fully-charged laptops that could function as iOS device chargers in a pinch.
With all those charging devices available, we kept both of our iPhones alive for several days. My wife forgot to turn her iPhone off one night before we went to shivery sleep; since it spent all night trying to cling to spotty cell networks, the battery was on its last legs by morning. When you cant charge overnight, be sure to turn your iPhone off, or at least activate Airplane Mode.
We intentionally didn't plug our iPhones into the battery cases or other charging devices at night, because we only wanted them to charge when we could manually stop charging as soon as the batteries were nearly full. Otherwise, wed needlessly drain extra stored-up juice from the chargers themselves.
I read on my iPad during the blackout -- clearing out the bulk of my Instapaper queue and reading a few iBooks -- with its brightness all the way down and Airplane Mode on. With relatively lengthy reading jags for a couple hours at a time, I squeezed five days of reading out of the iPad (a third-generation model) before its battery gave up.
One step at a time
Even now, more than a week after Sandy plowed its path of devastation, the cell reception around our home vacillates between awful and unusable, with patches of great and terrible service as we move about town.
Now, though, our power is back, so managing our batteries isn't a challenge any longer. Our new problem is finding reliable Internet access: Our home service is still out, and AT&T is offering EDGE speeds at best in our neighborhood. If I couldnt rely on the kindness of family friends, who are letting me use their Wi-Fi until our connection starts working again, Id need to consider a Verizon MiFi or a Verizon iPad with tethering; its the only cell carrier offering fast, reliable data in my area right now.
But, believe me, any connection at all is better than what we had a week ago.