How to make your iPhone battery last a lot longer!

By David Pogue
New York Times

A good friend of mine had
been complaining that her
iPhone 3GS battery was holding
less and less of a charge. When
we got together at 5 p.m. one
recent day, it was at 5 percent
full - and it had been fully
charged that morning. She had
barely used it all day.

The phone
was apparently running itself
dry simply by being turned on.
The single biggest battery
consumer is the screen
brightness. But it wasn't
especially bright on this phone.
So I suggested that she take
the phone to an Apple store to
get the $60 battery
replacement service.

In fact, there was an Apple store only
two blocks away, so I
accompanied her - and found
out, upon arrival, that there is
no $60 battery replacement
service! There's one for iPods,
but apparently not for the
iPhone.
There are plenty of do-it-
yourself and third-party
battery-replacement services
that advertise online, but the
Apple store Genius, named
Nicole, said none of that would
be necessary. She tested the
battery and found that it was
perfectly fine!

Instead, Nicole pointed out a
few things that were
contributing to my friend's
rapid battery depletion. I took
notes and thought I'd pass
them along.
* Push e-mail. This, I believe,
was the big one. My friend has
seven e-mail accounts, and her
phone was checking each of
them every 15 minutes. If you
turn off the "Push" feature, and
set it to Manually instead (in
Settings-Mail, Contacts,
Calendars-Fetch New Data), then
your iPhone checks for e-mail
only when you actually open
the e-mail app. Your battery
goes a lot farther.
(If you have a corporate
Exchange account, your
calendar and address-book data
will similarly be updated only
when you open those apps.)
* GPS checks. In Settings -
General-Location Services, you'll
see a list of all the apps on your
phone that are using your
phone's location feature to
know where you are. (It's a
combination of GPS, cell-tower
triangulation and, on some
phones, Wi-Fi hotspot
triangulation.) All of that
checking uses battery power,
too. My friend had dozens of
apps with Location Services
turned on, many of which
didn't really need to be on. She
turned most of them off.
* Notifications. Similarly, in
Settings - Notifications, you see
a list of apps that are allowed
to display pop-up notifications
(those blue text bubbles that
look like text messages). To do
that, they have to monitor
what's going on with your
phone - and that takes juice.
Turn off the ones you don't
really need.
* Background apps. Nicole the
Genius discovered that my
friend had a huge number of
apps open - maybe 40 of them.
She maintained that they were
using battery power, too, in the
background.
Now, I kept my mouth shut. But
I'd been led to believe that
background apps are generally
frozen into suspended
animation precisely so that
they don't use battery power.
In fact, Apple was criticized
when it introduced
"multitasking" in the latest
iPhone software, precisely
because apps don't actually
keep operating in the
background. Only a few
sanctioned features keep
running in the background
(Internet radio playback and
GPS tracking, for example).

Even so, Nicole quit all 40 of the
apps that were still open. (To
do that, double-press the Home
button to open the
multitasking app switcher. Hold
your finger down on any icon
until they all start wiggling. Tap
the little X close boxes to
manually quit open apps.)

Did the Nicole treatment work?
Very well indeed. The next day,
my friend's battery, by the
same time of day (5 p.m.), was
still at 80 percent!
So there you go: How to make
your iPhone battery last a lot
longer. For free. You're
welcome.