pedromdribeiro, consider this: “Apple is estimating one battery will last for 400 charges — probably about two years’ worth of use.” The battery will have a "full life" of about 400 complete charge cycles. Meaning it can charge 400 times from empty and still maintain 100% of its life. This does not mean that after the 400 cycles, it will go "poof" and no longer work:) If you run your battery down to zero every day and charge it back up over night after 400 days of doing this, your battery will drop to about 80 percent of its charging capacity and decrease from there over time. If you did the same thing but only used 50% of the battery everyday, charge it back up over night then it would be good for 800 days. Check on here as well as on here for more information. For now, enjoy your iPhone and the new battery. Hope this helps, good luck.