The nexus 5 is the best phone in this price range, it does come with a small battery & the camera is not the best considering other flagship models but the fact that you get the latest chipset from Qualcomm & the adreno 330 GPU along with 2GB ram & most important of all updates from google for the next 18 months at least makes this phone a value for money product, another stand out feature for me is Corning Gorilla glass 3 which means a screen guard is not required for the screen however some may disagree.
Pro & Cons have been discussed in many other reviews so I thought I would state a few battery saving tips.
1) Screen brightness set manually as per requirement & not on auto.
2) Turn Off Google Now if not required.
3) Uncheck Wi-fi scanning even when wi-fi is switched off.
4) Bluetooth, GPS, Wi-fi, NFC & other wireless features switched off when not required.
5)Vibrate on keypress also switched off.
6)Refrain from using Live wallpapers.
7) Keep Widget usage to a minimum & keep as few home screens as possible.
8) Manually update apps switch off auto-updates as constant search for updates online does drain battery.
9) Toggle between 2G/3G as per requirement, especially considering 3G reception is still not great in india.
10) Kill all apps that you dont want running in the background.
Some of the above are basic, others are tips which users may not be aware of