A Samsung Mobile Phone battery will last from 2 to 3 years and by that time you may be upgrading your entire mobile phone anyway to a newer model instead of replacing the battery.
So as long as you wait until the battery is getting nearly discharged and then recharge the battery you can help increase the lifespan.
I wouldn't worry to much though about the battery lifespan since like I mentioned you'll likely be replacing the entire phone before replacing the battery unless it's an expensive phone model that you want to keep and use longer than 3 years.