Disable location reporting and history

GPS is a huge battery hog, as it harnesses data
from the phone's GPS chip, cell phone towers,
and Wi-Fi hotspots to find your location. The
more a phone surveys your location, the more
battery it uses. And that goes beyond just Google
Maps.
Location reporting and location history are two
GPS-based services with somewhat unclear
motives. According to a Google Help page, the
services can be used in conjunction with any
other Google Apps, and may be used to improve
your experience.
Chances are you can probably live without them,
so disable these two features by going to
Settings > Location > Google Location Reporting.

Disable Google Now cards
Now is an unmatched personal assistant, but
some of its services -- which come in the form
of informational "cards" -- are tireless battery
drains.
For example, a card titled "Nearby places" shows
you nearby attractions when you travel to a place
that Google recognizes is out of your usual
routine. Cool? Yes. Necessary? No.
To disable cards, go to Google Now, then scroll
down to the very bottom, and tap the magic
wand. Here, you can pick the cards you actually
need. As a general guide, the GPS-reliant cards
will demand the most battery, so disable cards
like "Travel time" and "Nearby places" to see a
battery boost.

Wi-Fi scanning
It's well-known that when Wi-Fi is left enabled,
more energy is used. However, on Android , even
when Wi-Fi is disabled, a phone could still be
searching for networks.
To make sure this isn't happening, head to Wi-Fi
settings > Advanced. Here, uncheck the option
for Wi-Fi scanning.
Going forward, you'll have to connect to Wi-Fi
manually, but you'll get a longer battery life in
return.

Get out of sync
When you add an e-mail account to your phone,
Google assumes you'd like to sync just about
everything. That includes Google Play purchases,
Google Keep, and even photos.
That last one is killer: photos. Each time you
snap a picture, Google uploads it to your account
to back it up. For those who use their phone as
their primary camera (that's everyone, right?),
this can seriously hurt your battery life.

There are two ways to change this. Head to
settings and find your e-mail address under
Accounts. Tap the account name again to
access sync settings, where you can un-check
the items you don't want synced. Included there
is that "Google Photos" option.
Alternatively, head to the Gallery app > Settings,
and disable Google Photos Sync.

Use the battery tool
If you're unsure how energy-demanding an app
is, or you're wondering why your battery is
draining so quickly, use the Battery tool. The
feature shows you which apps use the most
battery, with the top two items almost always
being Screen and Wi-Fi. Goto settings and click on battery to see which apps are consuming your battery.

BONUS: search for any "Auto kill" apps on Google. Play store to kill running app automatically.

Coined from CNET.com

Buy Gionee M2, end of story ;-)

... Or any other phone with at least 4000 mAh of battery capacity.

hmmm