Samsung Galaxy S2 — Owners: What is your approximate battery life?

I had gingerbread 2.2.3 with battery life of approximate 4-6 hours with heavy use, 8-10 hours with moderate use, with stock ROM & stock battery. Now I updated via kies to gingerbread 2.3.6 with application Battery Doctor(by android doctor) & Battery XL conjointly it gives me battery life of approximate 8-10 hours with heavy use, 18-20 hours with moderate use,with stock ROM & stock battery.
Battery Doctor(by android doctor) & Battery XL applications are available on android market for free.

Just a quick tip - when you first get your phone it improves battery life drastically if you resist the temptation to use it straight away and give it a full charge for a few hours. It also helps maintain it if you regularly flatten the battery and give it a full charge.

Also, rooting your device can help you control the cpu speeds, making battery management easier.

On power saving mode about one day... In regular mode about 8-6 hours. Got too many applications

how can i increase my battery???

Well first of all I could never get the right time to charge it because I always needed it, but now I have the charger set on a timer very early in the morning. I have it timed so that it just finishes charging when it is time to get up, this way it is always fully charged. Mine takes nearly 4 hours to charge and I get up at 7am so it is set to come on around 3am. I find this very handy, you just have to remember to plug the phone in when you go to bed!

If my Data connection is on most of the day, the battery is flat about 6.30pm ish, but if I just have it on when I need it lasts me for a whole day.

Although don't be fooled! Once it was 72% when I went to bed so I thought oh it will be fine tomorrow, but the next morning it was 22%!! So don't get fooled like I did, and no apps were open and the Data connection was off.