Depends on lots of things Sanjay.
Quality of cells that make up the battery in the first place.
How hard they are worked when in use. Batteries have a specified discharge current rating. If that current (or more) is drawn on a regular basis or for extended periods, it will shorten the battery life.
Li-ion batteries used until they run out then charged will have a shorter life than those used and charged .
Buy the best quality you can afford. Use it and charge it. Best not to leave for long periods unused.
With a good battery 4-6 years is acheivable these days.