Which Latptop and Linux OS has better battery life ?

the more lightweight desktop, the longer battery life.
If you're familiar with Linux distros, you can take a look at any distro with Xfce or LXDE as environment.
For example, minimalistic Puppy Linux, Arch Linux, Xubuntu and so on.
If you would like to stay with a more comfortable and modern distro (Ubuntu, openSUSE, Fedora), you've to know your hardware specific tweaks.
This allow you to configure properly laptop-mode-tools and TLP, or even kernel options.
It's more more complicated, to decide which hardware will work better with Linux.
There's plenty of vendors.
Some laptop components work better with Linux, some worse.
It seems, that stick with Intel technology is the best option.
Intel CPU, Intel graphics, chipsets and you'll get the best support (some say, Intel drivers are the best, and if not - the more frequently patched).
But this all you should judge by yourself - I've tiny eeePC, which works10h on battery, and huge Dell XPS (I7, ATI, and so on), which can survive only around2.5h on battery (even under Win7).

Ubuntu is my favoritue 

I assume, you want to work in graphics mode.
General rule says - the more lightweight desktop, the longer battery life.
If you're familiar with Linux distros, you can take a look at any distro with Xfce or LXDE as environment.
For example, minimalistic Puppy Linux, Arch Linux, Xubuntu and so on.
If you would like to stay with a more comfortable and modern distro (Ubuntu, openSUSE, Fedora), you've to know your hardware specific tweaks.
This allow you to configure properly laptop-mode-tools and TLP, or even kernel options.
It's more more complicated, to decide which hardware will work better with Linux.
There's plenty of vendors.
Some laptop components work better with Linux, some worse.
It seems, that stick with Intel technology is the best option.
Intel CPU, Intel graphics, chipsets and you'll get the best support (some say, Intel drivers are the best, and if not - the more frequently patched).
But this all you should judge by yourself - I've tiny eeePC, which works10h on battery, and huge Dell XPS (I7, ATI, and so on), which can survive only around2.5h on battery (even under Win7).

Ubuntu is the best flavor for laptop

I like Ubuntu13.10

Debian is good one easy to use and very flexible.

Hi, Its Hp pavilion14 ultrabook b003tx with Windows864 bit is the best of the class for battery backup.
Dont install windows7 or linux, it reduces your backup time by3/4.
Regards, Sajan.S

First of all battery life depend on two major things "period as well as uses".

 

1.) About Period :

Normally we have seen during1st year of purchase most of the laptop battery gives good performance and after it starts degrade. Might be electronic / manufacture reason behind this.

 

2.) About Uses:

Here we can discuss about Operating System (might be Window, Linux and other).

for example In window  OS we can go through hardware & software profile to minimize the uses of battery.

In Linux OS also gives you more freedom to stop/disable unused service Or features those uses power (e.g. Bluetooth, USB, CD/DVD ROM etc.)  to optimized OS performance as well as battery uses.

 

Conclusion :

Battery life depend on manufacturer as well as its way of uses.

Good questions , i i thing Ubuntu Save more than outher opreting System battery life bcz all application work smoothly

Im using Lubuntu , an LXDE based Ubuntu distro for my netbook. Gave me superb battery life, over3 hours of movie, quite good for1st generation netbook. I could barely get1 hour on Windows XP.