With your usage I can tell you for sure that the N9 will not last the entire day on a single charge.You would need to carry your charger with you to charge it up mid-way through the day.

Im using an N9 64GB too which I got from USA and with 3G on all the time I have to charge my phone in between for it to last enough to reach back home.

Also as mentioned above the Video Player of the N9 is rather picky at what it plays.. So picky that at times it wont even play what is recorded by the phone itself.

In the price range you mentioned the Lumia 620 is a good bet with a rather good battery but if you can manage to push your budget a bit more you can get the Nokia 808 Pureview which is going for a steal in India now or the Lumia 720 which has a crazy long battery life.

EBay for Nokia 720 : http://www.ebay.in/itm/ws/eBayISAPI....m=261212648853

Ebay for Nokia 808 PV : http://www.ebay.in/itm/Nokia-808pure...item19dc77133f


Now im not criticizing the N9. I love my N9 for what it is but it just does what it feels like at times and thats what drives me crazy. Just wished for a slightly better battery life but that AMOLED and the white backgrounds on the internet dont really go along to help the battery.

So make your choice wisely....