When your iPhone battery blows after hundreds of charge cycles, Apple doesn't have very good options to fix it. And rest assured your iPhone will need a battery replacement, most likely within two years.It's amazing how fast an iPhone battery deteriorates, typically ending up on death row in 18 months or less. Every time you go through a charge cycle, for instance, you'll permanently lose anywhere from 30 seconds to a minute of battery capacity.Typically, you'll get 250 to 500 charge cycles before a lithium ion battery has outlived its usefulness, says Aaron Vronko, CEO of Raid Repair, which services broken iPods and iPhones and replaces worn-out batteries for $50.If you're an iPhone addict, an original battery can become unbearable in a matter of months. Six months ago, I took Golfshot GPS app on a test drive at a local course and finished the round with a battery percentage in the low 50s, roughly half my golf score (starting with 100 percent charge). Last weekend, I had to shut down my iPhone on the 14th hole because the iPhone's battery life was at a miserable 11 percent.An Apple Store manager at a Bay Area location says his iPhone 3GS battery life is down maybe 30 percent since he first got it in June last year. (We chatted about batteries before he sold me a Mophie Juice Pack Air.) The battery would last a day and a half when new; but today, he must charge it every night and maybe a second time during a day of heavy use.But if you're unhappy with your iPhone's battery life, an Apple Store might not be the best place to take it. Apple doesn't even offer an optional iPhone battery replacement service\u2014only a warranty.The iPhone comes with a year warranty, so if you're still under warranty you can get your poorly performing iPhone battery tested at the Genius Bar. Just be sure to make an appointment. The Genius Bar will run your iPhone through a software test, which will indicate the number of charge cycles as well as how your battery performance compares to a new iPhone battery.Here's the rub, though: Apple will replace your iPhone for free if the battery is operating at 50 percent or less of a new iPhone. But if your iPhone is operating at 50 percent within a year, then chances are your iPhone battery was defective in the first place. This actually has nothing to do with the natural deterioration of a lithium ion battery.You could purchase Apple Care for $70, which extends your warranty another year. But you'll need to buy Apple Care before your warranty expires. Since iPhone batteries need to be replaced every 18 months on average, Apple Care covers this time frame.The problem with this route, however, is that your iPhone battery must hit 50 percent or less of a new iPhone before Apple replaces it\u2014and there's no guarantee that your iPhone battery capacity will have degraded this much by its second year.Besides, would you want an iPhone with almost half battery degradation? Sure, Apple Care covers more than just batteries gone bad, but as a de facto battery replacement service, it's not a good bet.The better option is to take your iPhone to a third-party service provider like Rapid Repair when you feel you need more juice. "Just make sure the provider is Apple authorized so as not to void your warranty," the Apple Store manager said.Lastly, be selective when choosing a service provider or battery vendor.One reader commented: "I ordered a replacement battery online ($4.99) and it arrived from Hong Kong several days later. Took me about 20 minutes to replace the battery. It's not that hard. Problem is, the 'new' battery was worse than the old battery!"Tom Kaneshige is a senior writer for CIO.com in Silicon Valley. Send him an email at firstname.lastname@example.org. Or follow him on Twitter @kaneshige. Follow everything from CIO.com on Twitter @CIOonline.