If you've ever wondered how long it will take you to replace your iPhone's battery after all that email reading, map browsing, film strip watching and music listening, you're definitely not alone. Tick-tocking its way into the news is the fact that PC Magazine took their best leap forward and gave an admittedly unscientific, "best guess" as to when your iPhone's battery pack would begin to degrade: 675 days.

Of course, it's a mixture of mathematical computations, factual statements from Apple and more than a share of speculation on PC Mag's part. Apple said that an iPhone's battery would hold only 80% the original amount of charge after 400 times of charging, clocked at about 4 hours via five volts of USB supply.

And coupled with the 30 hours of iPhone use from a single charge, PC Mag estimates that 34 hours (1.5 days per charge approximated) over an optimistic 450 days of good battery life would amount to 675 days of battery life all-in-all (or 599.85 days at 1.333 days per charge, to be mathematically accurate).

Just don't panic if you try they little countdown tool provided at the Read link below. After all, it's just a best guess and your use of the iPhone could drive your own battery life to last phenomenally different from what PC Mag indicates.